Substituted indolepyridinium as anti-infective compounds

ABSTRACT

The present invention concerns the compounds of formula (I) 
     
       
         
         
             
             
         
       
     
     their N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs, esters and metabolites, wherein n is 1, 2 or 3; R 1  is H, CN, halo, aminoC(═O), C(═O)OH, C 1-4 alkyloxyC(═O), C 1-4 alkylC(═O), mono- or di(C 1-4 alkyl)aminoC(═O), arylaminoC(═O), N-(aryl)-N—(C 1-4 alkyl)aminoC(═O), methanimidamidyl, N-hydroxy-methanimidamidyl, mono- or di(C 1-4 alkyl)methanimidamidyl, Het 1  or Het 2 ; R 2  is H, C 1-10 alkyl, C 2-10 alkenyl, C 3-7 cycloalkyl, wherein said C 1-10 alkyl, C 2-10 alkenyl and C 3-7 cycloalkyl may be optionally substituted; R 3  is nitro, cyano, amino, halo, hydroxy, C 1-4 alkyloxy, hydroxyC(═O), aminoC(═O), C 1-4 alkyloxyC(═O), mono- or di(C 1-4 alkyl)aminoC(═O), C 1-4 alkylC(═O), methanimidamidyl, mono- or di(C 1-4 alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or Het 1 ; for use as a medicine. The invention further relates to a novel subgroup of the compounds of formula (I), and to compositions comprising compounds of formula (I).

The present invention relates to the use of substituted indolepyridiniumas anti-infective compounds, and to pharmaceutical compositions anddiagnostic kits comprising them. The present invention also concernscombinations of the present substituted indolepyridinium compounds withanother anti-retroviral agent. It further relates to their use in assaysas reference compounds or as reagents.

The virus causing the acquired immunodeficiency syndrome (AIDS) is knownby different names, including T-lymphocyte virus III (HTLV-III) orlymphadenopathy-associated virus (LAV) or AIDS-related virus (ARV) orhuman immunodeficiency virus (HIV). Up until now, two distinct familieshave been identified, i.e. HIV-1 and HIV-2. Hereinafter, HIV will beused to generically denote these viruses.

AIDS patients are currently treated with HIV protease inhibitors (PIs),nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleosidereverse transcriptase inhibitors (NNRTIs) and nucleotide reversetranscriptase inhibitors (NtRTIs). Those compounds are oftenadministered in drug cocktails comprising two or more compounds of theabove classes of drugs. Despite the fact that these antiretrovirals arevery useful, they have a common limitation, namely, the targeted enzymesin the HIV virus are able to mutate in such a way that the known drugsbecome less effective, or even ineffective against these mutant HIVviruses. Or, in other words, the HIV virus creates an ever-increasingresistance against the available drugs.

Resistance of retroviruses, and in particular the HIV virus, againstinhibitors is a major cause of therapy failure. For instance, half ofthe patients receiving anti-HIV combination therapy do not respond fullyto the treatment, mainly because of resistance of the virus to one ormore drugs used. Moreover, it has been shown that resistant virus iscarried over to newly infected individuals, resulting in severelylimited therapy options for these drug-naive patients. Therefore, thereis a need for new compounds for retrovirus therapy, more particularlyfor AIDS therapy. This need is particularly acute for compounds that areactive not only on wild type HIV virus, but also on the increasinglymore common resistant HIV viruses.

Known antiretrovirals, often administered in a combination therapyregimen, will eventually cause resistance as stated above. This oftenmay force the physician to boost the plasma levels of the active drugsin order for said antiretrovirals to regain effectivity against themutated HIV viruses. The consequence of which is a highly undesirableincrease in pill burden. Boosting plasma levels may also lead to anincreased risk of non-compliance with the prescribed therapy.

Currently used commercially available HIV reverse transcriptaseinhibitors belong to three different classes, the NRTIs such aszidovudine, didanosine, zalcibatine, stavudine, abacavir and lamivudine,the NtRTIs such as tenofovir, and NNRTIs such as nevirapine, delavirdineand efavirenz. The NRTIs and NtRTIs are base analogs that target theactive site of HIV reverse transcriptase (RT). Currently used NNRTI areknown for rapid emergence of resistance due to mutations at amino acidsthat surround the NNRTI binding site (J AIDS 2001, 26, S25-S33).

Thus, there is a high medical need for anti-infective compounds thattarget HIV reverse transcriptase, in particular anti-retroviralcompounds that are able to delay the occurrence of resistance and thatcombat a broad spectrum of mutants of the HIV virus.

WO 02/055520 and WO 02/059123 disclose benzoylalkylindolepyridiniumcompounds as antiviral compounds. Ryabova et al. disclose the synthesisof certain benzoylalkylindolepyridinium compounds (Russian Chem. Bull.2001, 50(8), 1449-1456) (Chem. Heterocycl. Compd. (Engl. Translat.)36;3; 2000; 301-306; Khim. Geterotsikl. Soedin.; RU; 3; 2000; 362-367).

It is now found that substituted indolepyridinium compounds of formula(I),

their N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs,esters and metabolites,wherein

-   n is 1, 2 or 3;-   R₁ is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,    C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- or    di(C₁₋₄alkyl)aminocarbonyl, arylaminocarbonyl,    N-(aryl)-N—(C₁₋₄alkyl)aminocarbonyl, methanimidamidyl,    N-hydroxy-methanimidamidyl, mono- or di(C₁₋₄alkyl)methanimidamidyl,    Het₁ or Het₂;-   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl, wherein    said C₁₋₁₀alkyl, C₂₋₁₀alkenyl and C₃₋₇cycloalkyl, each individually    and independently, may be optionally substituted with a substituent    selected from the group consisting of cyano, NR_(4a)R_(4b),    pyrrolidinyl, piperidinyl, homopiperidinyl, piperazinyl,    4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, thiomorpholinyl,    1-oxothiomorpholinyl, 1,1-dioxo-thiomorpholinyl, aryl, furanyl,    thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl,    isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl,    tetrazolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl,    hydroxycarbonyl, C₁₋₄alkylcarbonyl, N(R_(4a)R_(4b))carbonyl,    C₁₋₄alkyloxycarbonyl, pyrrolidin-1-ylcarbonyl,    piperidin-1-ylcarbonyl, homopiperidin-1-ylcarbonyl,    piperazin-1-ylcarbonyl, 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl,    morpholin-1-ylcarbonyl, thiomorpholin-1-ylcarbonyl,    1-oxothiomorpholin-1-ylcarbonyl and    1,1-dioxo-thiomorpholin-1-ylcarbonyl;-   R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,    hydroxycarbonyl, aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- or    di(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, methanimidamidyl,    mono- or di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl    or Het₁;-   R_(4a) is hydrogen, C₁₋₄alkyl or C₁₋₄alkyl substituted with a    substituent selected from the group consisting of amino, mono- or    di(C₁₋₄alkyl)amino, pyrrolidinyl, piperidinyl, homopiperidinyl,    piperazinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl,    thiomorpholinyl, 1-oxothiomorpholinyl and 1,1-dioxo-thiomorpholinyl;-   R_(4b) is hydrogen, C₁₋₄alkyl or C₁₋₄alkyl substituted with a    substituent selected from the group consisting of amino, mono- or    di(C₁₋₄alkyl)amino, pyrrolidinyl, piperidinyl, homopiperidinyl,    piperazinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl,    thiomorpholinyl, 1-oxothiomorpholinyl and 1,1-dioxo-thiomorpholinyl;-   aryl is phenyl optionally substituted with one or more substituents    each individually selected from the group consisting of C₁₋₆alkyl,    C₁₋₄alkoxy, halo, hydroxy, amino, trifluoromethyl, cyano, nitro,    hydroxyC₁₋₆alkyl, cyanoC₁₋₆alkyl, mono- or di(C₁₋₄alkyl)amino,    aminoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl;-   Het₁ is a 5-membered ring system wherein one, two, three or four    ring members are heteroatoms each individually and independently    selected from the group consisting of nitrogen, oxygen and sulfur,    and wherein the remaining ring members are carbon atoms; and, where    possible, any nitrogen ring member may optionally be substituted    with C₁₋₄alkyl; any ring carbon atom may, each individually and    independently, optionally be substituted with a substituent selected    from the group consisting of C₁₋₄alkyl, C₂₋₆alkenyl, C₃₋₇cycloalkyl,    hydroxy, C₁₋₄alkoxy, halo, amino, cyano, trifluoromethyl,    hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)amino,    aminoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl,    aminoC₂₋₆alkenyl, mono- or di(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl,    thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl,    isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl,    tetrazolyl, aryl, hydroxycarbonyl, aminocarbonyl,    C₁₋₄alkyloxycarbonyl, mono- or di(C₁₋₄alkyl)aminocarbonyl,    C₁₋₄alkylcarbonyl, oxo, thio; and wherein any of the foregoing    furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl,    isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl and    triazolyl moieties may optionally be substituted with C₁₋₄alkyl;-   Het₂ is pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl or triazinyl,    wherein any ring carbon atom of each of said 6-membered nitrogen    containing aromatic rings may optionally be substituted with a    substituent selected from the group consisting of C₁₋₄alkyl;    inhibit the replication of HIV virus.

In one embodiment, the invention relates to the inhibition of thereplication of HIV virus by substituted indolepyridinium compounds offormula (I) wherein R₁ is cyano, C₁₋₄alkylaminocarbonyl orC₁₋₄alkyloxycarbonyl; R₂ is hydrogen or C₁₋₆alkyl; n is 1 and R₃ isnitro.

The compounds of formula (I) are active against wild type HIV virus andalso against a variety of mutant HIV viruses including mutant HIVviruses exhibiting resistance against commercially available reversetranscriptase (RT) inhibitors. The compounds of formula (I) aretherefore useful as a medicine, and thus also useful in the manufactureof a medicament useful for preventing, treating or combating infectionor disease associated with HIV infection.

A subgroup of the compounds of formula (I) is deemed novel and consistsof those compounds of formula (I) provided they are different from

-   2,5-dihydro-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile,    and-   2,5-dihydro-5-methyl-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile.

Thus, the present invention also concerns the compounds of formula (I)having the formula

their N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs,esters and metabolites,wherein

-   n is 1, 2 or 3;-   R₁ is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,    C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- or    di(C₁₋₄alkyl)aminocarbonyl, arylaminocarbonyl,    N-(aryl)-N—(C₁₋₄alkyl)aminocarbonyl, methanimidamidyl,    N-hydroxy-methanimidamidyl, mono- or di(C₁₋₄alkyl)methanimidamidyl,    Het₁ or Het₂;-   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl, wherein    said C₁₋₁₀alkyl, C₂₋₁₀alkenyl and C₃₋₇cycloalkyl, each individually    and independently, may be optionally substituted with a substituent    selected from the group consisting of cyano, NR_(4a)R_(4b),    pyrrolidinyl, piperidinyl, homopiperidinyl, piperazinyl,    4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, thiomorpholinyl,    1-oxothiomorpholinyl, 1,1-dioxo-thiomorpholinyl, aryl, furanyl,    thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl,    isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl,    tetrazolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl,    hydroxycarbonyl, C₁₋₄alkylcarbonyl, N(R_(4a)R_(4b))carbonyl,    C₁₋₄alkyloxycarbonyl, pyrrolidin-1-ylcarbonyl,    piperidin-1-ylcarbonyl, homopiperidin-1-ylcarbonyl,    piperazin-1-ylcarbonyl, 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl,    morpholin-1-ylcarbonyl, thiomorpholin-1-ylcarbonyl,    1-oxothiomorpholin-1-ylcarbonyl and    1,1-dioxo-thiomorpholin-1-ylcarbonyl;-   R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,    hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl,    C₁₋₄alkyloxycarbonyl, mono- or di(C₁₋₄alkyl)-aminocarbonyl,    C₁₋₄alkylcarbonyl, methanimidamidyl, mono- or    di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or Het₁;-   R_(4a) is hydrogen, C₁₋₄alkyl or C₁₋₄alkyl substituted with a    substituent selected from the group consisting of amino, mono- or    di(C₁₋₄alkyl)amino, pyrrolidinyl, piperidinyl, homopiperidinyl,    piperazinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl,    thiomorpholinyl, 1-oxothiomorpholinyl and 1,1-dioxo-thiomorpholinyl;-   R_(4b) is hydrogen, C₁₋₄alkyl or C₁₋₄alkyl substituted with a    substituent selected from the group consisting of amino, mono- or    di(C₁₋₄alkyl)amino, pyrrolidinyl, piperidinyl, homopiperidinyl,    piperazinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl,    thiomorpholinyl, 1-oxothiomorpholinyl and 1,1-dioxo-thiomorpholinyl;-   aryl is phenyl optionally substituted with one or more substituents    each individually selected from the group consisting of C₁₋₆alkyl,    C₁₋₄alkoxy, halo, hydroxy, amino, trifluoromethyl, cyano, nitro,    hydroxyC₁₋₆alkyl, cyanoC₁₋₆alkyl, mono- or di(C₁₋₄alkyl)amino,    aminoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl;-   Het₁ is a 5-membered ring system wherein one, two, three or four    ring members are heteroatoms each individually and independently    selected from the group consisting of nitrogen, oxygen and sulfur,    and wherein the remaining ring members are carbon atoms; and, where    possible, any nitrogen ring member may optionally be substituted    with C₁₋₄alkyl; any ring carbon atom may, each individually and    independently, optionally be substituted with a substituent selected    from the group consisting of C₁₋₄alkyl, C₂₋₆alkenyl, C₃₋₇cycloalkyl,    hydroxy, C₁₋₄alkoxy, halo, amino, cyano, trifluoromethyl,    hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)amino,    aminoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl,    aminoC₂₋₆alkenyl, mono- or di(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl,    thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl,    isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl,    tetrazolyl, aryl, hydroxycarbonyl, aminocarbonyl,    C₁₋₄alkyloxycarbonyl, mono- or di(C₁₋₄alkyl)aminocarbonyl,    C₁₋₄alkylcarbonyl, oxo, thio; and wherein any of the foregoing    furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl,    isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl and    triazolyl moieties may optionally be substituted with C₁₋₄alkyl;-   Het₂ is pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl or triazinyl,    wherein any ring carbon atom of each of said 6-membered nitrogen    containing aromatic rings may optionally be substituted with a    substituent selected from the group consisting of C₁₋₄alkyl;    provided that the compound is different from-   2,5-dihydro-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile,    and-   2,5-dihydro-5-methyl-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile.

One embodiment concerns the compounds of formula (I), their N-oxides,salts, stereoisomeric forms, racemic mixtures, prodrugs, esters andmetabolites, wherein R₁ is cyano, C₁₋₄alkylaminocarbonyl orC₁₋₄alkyloxycarbonyl; R₂ is hydrogen or C₁₋₆alkyl; n is 1 and R₃ isnitro; provided that the compound is different from

-   2,5-dihydro-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile,    and-   2,5-dihydro-5-methyl-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile.

The term “C₁₋₄alkyl” as a group or part of a group defines straight andbranched chained saturated hydrocarbon radicals having from 1 to 4carbon atoms, such as, for example, methyl, ethyl, propyl, butyl,2-methyl-propyl and the like. The term “C₁₋₆alkyl” as a group or part ofa group defines straight and branched chained saturated hydrocarbonradicals having from 1 to 6 carbon atoms such as, for example, thegroups defined for C₁₋₄alkyl and pentyl, hexyl, 2-methylbutyl,3-methylpentyl and the like.

The term “C₂₋₆alkyl” as a group or part of a group defines straight andbranched chained saturated hydrocarbon radicals having from 2 to 6carbon atoms such as for example, ethyl, propyl, butyl, 2-methyl-propyl,pentyl, hexyl, 2-methylbutyl, 3-methylpentyl and the like.

The term “C₁₋₁₀alkyl” as a group or part of a group defines straight andbranched chained saturated hydrocarbon radicals having from 1 to 10carbon atoms such as, for example, the groups defined for C₁₋₆alkyl andheptyl, octyl, nonyl, decyl and the like. The term C₂₋₆alkenyl as agroup or part of a group defines straight and branched chainedhydrocarbon radicals having saturated carbon-carbon bonds and at leastone double bond, and having from 2 to 6 carbon atoms, such as, forexample, ethenyl, prop-1-enyl, but-1-enyl, but-2-enyl, pent-1-enyl,pent-2-enyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, 1-methyl-pent-2-enyland the like.

The term C₂₋₁₀alkenyl as a group or part of a group defines straight andbranched chained hydrocarbon radicals having saturated carbon-carbonbonds and at least one double bond, and having from 2 to 10 carbonatoms, such as, for example, the groups of C₂₋₆alkenyl and hept-1-enyl,hept-2-enyl, hept-3-enyl, oct-1-enyl, oct-2-enyl, oct-3-enyl,non-1-enyl, non-2-enyl, non-3-enyl, non-4-enyl, dec-1-enyl, dec-2-enyl,dec-3-enyl, dec-4-enyl, 1-methyl-pent-2-enyl and the like.

The term C₃₋₇cycloalkyl is generic to cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and cycloheptyl.

The term halo is generic to fluoro, chloro, bromo or iodo.

The term methanimidamidyl is the radical name for H₂N—CH═NH followingthe Chemical Abstracts Nomenclature (CAS). Like wiseN-hydroxy-methanimidamidyl is CAS radical name for H₂N—CH═N—OH.

The term “C₆₋₁₄aryl” means an aromatic hydrocarbon ring having from 6 to14 ring members such as, for example, phenyl, naphthalene, anthraceneand phenanthrene.

It should be noted that different isomers of the various heterocyclesmay exist within the definitions as used throughout the specification.For example, oxadiazolyl may be 1,2,4-oxadiazolyl or 1,3,4-oxadiazolylor 1,2,3-oxadiazolyl; likewise for thiadiazolyl which may be1,2,4-thiadiazolyl or 1,3,4-thiadiazolyl or 1,2,3-thiadiazolyl; pyrrolylmay be 1H-pyrrolyl or 2H-pyrrolyl.

It should also be noted that the radical positions on any molecularmoiety used in the definitions may be anywhere on such moiety as long asit is chemically stable. For instance pyridyl includes 2-pyridyl,3-pyridyl and 4-pyridyl; pentyl includes 1-pentyl, 2-pentyl and3-pentyl.

When any variable (e.g. halogen or C₁₋₄alkyl) occurs more than one timein any constituent, each definition is independent.

The term “prodrug” as used throughout this text means thepharmacologically acceptable derivatives such as esters, amides andphosphates, such that the resulting in vivo biotransformation product ofthe derivative is the active drug as defined in the compounds of formula(I). The reference by Goodman and Gilman (The Pharmaco-logical Basis ofTherapeutics, 8^(th) ed, McGraw-Hill, Int. Ed. 1992, “Biotransformationof Drugs”, p 13-15) describing prodrugs generally is herebyincorporated. Prodrugs of a compound of the present invention areprepared by modifying functional groups present in the compound in sucha way that the modifications are cleaved, either by routine manipulationor in vivo, to the parent compound.

Prodrugs are characterized by excellent aqueous solubility, increasedbioavailability and are readily metabolized into the active inhibitorsin vivo.

For therapeutic use, the salts of the compounds of formula (I) are thosewherein the counterion is pharmaceutically or physiologicallyacceptable. However, salts having a pharmaceutically unacceptablecounterion may also find use, for example, in the preparation orpurification of a pharmaceutically acceptable compound of formula (I).All salts, whether pharmaceutically acceptable or not are includedwithin the ambit of the present invention.

The pharmaceutically acceptable or physiologically tolerable additionsalt forms which the compounds of the present invention are able to formcan conveniently be prepared using the appropriate acids, such as, forexample, inorganic acids such as hydrohalic acids, e.g. hydrochloric orhydrobromic acid; sulfuric; hemisulphuric, nitric; phosphoric and thelike acids; or organic acids such as, for example, acetic, aspartic,dodecyl-sulphuric, heptanoic, hexanoic, nicotinic, propanoic,hydroxyacetic, lactic, pyruvic, oxalic, malonic, succinic, maleic,fumaric, malic, tartaric, citric, methanesulfonic, ethanesulfonic,benzenesulfonic, p-toluenesulfonic, cyclamic, salicylic,p-amino-salicylic, pamoic and the like acids.

Conversely said acid addition salt forms can be converted by treatmentwith an appropriate base into the free base form.

The compounds of formula (I) containing an acidic proton may also beconverted into their non-toxic metal or amine addition salt form bytreatment with appropriate organic and inorganic bases. Appropriate basesalt forms comprise, for example, the ammonium salts, the alkali andearth alkaline metal salts, e.g. the lithium, sodium, potassium,magnesium, calcium salts and the like, salts with organic bases, e.g.the benzathine, N-methyl, -D-glucamine, hydrabamine salts, and saltswith amino acids such as, for example, arginine, lysine and the like.

Conversely said base addition salt forms can be converted by treatmentwith an appropriate acid into the free acid form.

The term “salts” also comprises the hydrates and the solvent additionforms that the compounds of the present invention are able to form.Examples of such forms are e.g. hydrates, alcoholates and the like.

The N-oxide forms of the present compounds are meant to comprise thecompounds of formula (I) wherein one or several nitrogen atoms areoxidized to the so-called N-oxide.

The present compounds may also exist in their tautomeric forms. Suchforms, although not explicitly indicated in the above formula areintended to be included within the scope of the present invention. Forexample, within the definition of Het, a 5 membered aromatic heterocyclesuch as for example an 1,2,4-oxadiazole may be substituted with ahydroxy or a thio group in the 5-position, thus being in equilibriumwith its respective tautomeric form as depicted below.

The term stereochemically isomeric forms of compounds of the presentinvention, as used hereinbefore, defines all possible compounds made upof the same atoms bonded by the same sequence of bonds but havingdifferent three-dimensional structures which are not interchangeable,which the compounds of the present invention may possess.

Unless otherwise mentioned or indicated, the chemical designation of acompound encompasses the mixture of all possible stereochemicallyisomeric forms which said compound may possess. Said mixture may containall diastereomers and/or enantiomers of the basic molecular structure ofsaid compound. All stereochemically isomeric forms of the compounds ofthe present invention both in pure form or in admixture with each otherare intended to be embraced within the scope of the present invention.

Pure stereoisomeric forms of the compounds and intermediates asmentioned herein are defined as isomers substantially free of otherenantiomeric or diastereomeric forms of the same basic molecularstructure of said compounds or intermediates. In particular, the term‘stereoisomerically pure’ concerns compounds or intermediates having astereoisomeric excess of at least 80% (i.e. minimum 90% of one isomerand maximum 10% of the other possible isomers) up to a stereoisomericexcess of 100% (i.e. 100% of one isomer and none of the other), more inparticular, compounds or intermediates having a stereoisomeric excess of90% up to 100%, even more in particular having a stereoisomeric excessof 94% up to 100% and most in particular having a stereoisomeric excessof 97% up to 100%. The terms ‘enantiomerically pure’ and‘diastereomerically pure’ should be understood in a similar way, butthen having regard to the enantiomeric excess, respectively thediastereomeric excess of the mixture in question.

Pure stereoisomeric forms of the compounds and intermediates of thisinvention may be obtained by the application of art-known procedures.For instance, enantiomers may be separated from each other by theselective crystallization of their diastereomeric salts with opticallyactive acids or bases. Examples thereof are tartaric acid,dibenzoyl-tartaric acid, ditoluoyltartaric acid and camphorsulfonicacid. Alternatively, enantiomers may be separated by chromatographictechniques using chiral stationary phases. Said pure stereochemicallyisomeric forms may also be derived from the corresponding purestereochemically isomeric forms of the appropriate starting materials,provided that the reaction occurs stereospecifically. Preferably, if aspecific stereoisomer is desired, said compound will be synthesized bystereospecific methods of preparation. These methods will advantageouslyemploy enantiomerically pure starting materials.

The diastereomeric racemates of formula (I) can be obtained separatelyby conventional methods. Appropriate physical separation methods thatmay advantageously be employed are, for example, selectivecrystallization and chromatography, e.g. column chromatography.

The present invention is also intended to include all isotopes of atomsoccurring on the present compounds. Isotopes include those atoms havingthe same atomic number but different mass numbers. By way of generalexample and without limitation, isotopes of hydrogen include tritium anddeuterium. Isotopes of carbon include C-13 and C-14.

Whenever used hereinafter, the term “compounds of formula (I)”, or “thepresent compounds” or similar term is meant to include the compounds ofgeneral formula (I), their N-oxides, salts, stereoisomeric forms,racemic mixtures, prodrugs, esters and metabolites, as well as theirquaternized nitrogen analogues. An interesting subgroup of the compoundsof formula (I) or any subgroup thereof are the N-oxides, salts and allthe stereoisomeric forms of the compounds of formula (I).

In one embodiment, n is 1 and the R₃ group on the phenyl ring in thecompound of formula (I) is in para-position vis-à-vis the nitrogen atomin the fused pyridine moiety as depicted herein below and hereinafterreferred to as compounds of formula (II)

An interesting subgroup of the compounds of formula (II) are thosecompounds of formula (II), hereinafter referred to compounds of formula(II-a), wherein R₃ is nitro.

A particular group of compounds are those compounds of formula (I)wherein R₁ is cyano, methyloxycarbonyl, methylaminocarbonyl,ethyloxycarbonyl and ethylaminocarbonyl, more in particular wherein R₁is cyano, ethyloxycarbonyl and ethylaminocarbonyl, even more inparticular wherein R₁ is cyano.

Another particular group of compounds are those compounds of formula (I)wherein R₂ is hydrogen or C₁₋₄alkyl, more in particular wherein R₂ ishydrogen or methyl, even more in particular wherein R₂ is methyl.

Yet another particular group of compounds are those compounds of formula(I) wherein R₁ is cyano and R₂ is hydrogen or methyl.

A particular group of novel compounds are those compounds of formula (I)wherein R₁ is C₁₋₄alkylaminocarbonyl or C₁₋₄alkyloxycarbonyl.

Another particular group of novel compounds are those compounds offormula (I) wherein R₁ is C₁₋₄alkylaminocarbonyl or C₁₋₄alkyloxycarbonyland R₂ is hydrogen or methyl.

Another particular group of novel compounds are those compounds offormula (I) wherein R₁ is methyloxycarbonyl, methylaminocarbonyl,ethyloxycarbonyl or ethylaminocarbonyl, and R₂ is hydrogen or methyl.

Another particular group of novel compounds are those compounds offormula (I) wherein R₂ is C₂₋₆alkyl.

Another particular group of novel compounds are those compounds offormula (I), wherein when R₁ is cyano then R₂ is different from hydrogenor methyl.

Yet another particular group of compounds are those compounds of formula(I) wherein R₂ is hydrogen or C₁₋₄alkyl, and the nitro group on thephenyl ring is in the ortho or meta position vis-à-vis the nitrogen atomin the fused pyridine moiety.

A suitable group of compounds are those compounds of formula (I) as asalt, wherein the salt is selected from trifluoroacetate, fumarate,chloroacetate, methanesulfonate, oxalate, acetate and citrate.

An interesting subgroup of the compounds of formula (I) are thosecompounds of formula (I) or subgroups thereof wherein any combination ofthe following restrictions applies

-   -   n is 1 or 2, more in particular wherein n is 1;    -   R₁ is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,        C₁₋₄alkyloxycarbonyl, arylaminocarbonyl,        N-hydroxy-methanimidamidyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, Het₁ or Het₂;    -   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or        C₁₋₁₀alkyl substituted with substituent selected from the group        consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,        4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl,        pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,        C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl;    -   R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,        hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl,        C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or        Het₁;    -   R_(4a) is C₁₋₄alkyl;    -   R_(4b) is C₁₋₄alkyl or C₁₋₄alkyl substituted morpholinyl;    -   aryl is phenyl optionally substituted with one or more        substituents each individually selected from the group        consisting of C₁₋₆alkyl, C₁₋₄alkoxy, cyano, nitro;    -   Het₁ is a 5-membered ring system wherein one, two, three or four        ring members are heteroatoms each individually and independently        selected from the group consisting of nitrogen, oxygen and        sulfur, and wherein the remaining ring members are carbon atoms;        and, where possible, any nitrogen ring member may optionally be        substituted with C₁₋₄alkyl; any ring carbon atom may, each        individually and independently, optionally be substituted with a        substituent selected from the group consisting of C₁₋₄alkyl,        C₃₋₇cycloalkyl, halo, cyano, trifluoromethyl, cyanoC₁₋₄alkyl,        mono- or di(C₁₋₄alkyl)amino, mono- or        di(C₁₋₄alkyl)aminoC₂₋₆alkenyl, isoxazolyl, aryl,        hydroxycarbonyl, C₁₋₄alkyloxycarbonyl, oxo, thio; and wherein        the foregoing isoxazolyl may optionally be substituted with        C₁₋₄alkyl;    -   Het₂ is pyridyl.

Examples of such combinations of the above mentioned restrictions arefor instance the combination of

-   -   n is 1 or 2, more in particular wherein n is 1; and    -   R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,        hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl,        C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or        Het₁.        or the combination of    -   R₁ is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,        C₁₋₄alkyloxycarbonyl, arylaminocarbonyl,        N-hydroxy-methanimidamidyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, Het₁ or Het₂; and    -   aryl is phenyl optionally substituted with one or more        substituents each individually selected from the group        consisting of C₁₋₆alkyl, C₁₋₄alkoxy, cyano, nitro; and    -   Het₁ is a 5-membered ring system wherein one, two, three or four        ring members are heteroatoms each individually and independently        selected from the group consisting of nitrogen, oxygen and        sulfur, and wherein the remaining ring members are carbon atoms;        and, where possible, any nitrogen ring member may optionally be        substituted with C₁₋₄alkyl; any ring carbon atom may, each        individually and independently, optionally be substituted with a        substituent selected from the group consisting of C₁₋₄alkyl,        C₃₋₇cycloalkyl, halo, cyano, trifluoromethyl, cyanoC₁₋₄alkyl,        mono- or di(C₁₋₄alkyl)amino, mono- or        di(C₁₋₄alkyl)aminoC₂₋₆alkenyl, isoxazolyl, aryl,        hydroxycarbonyl, C₁₋₄alkyloxycarbonyl, oxo, thio; and wherein        the foregoing isoxazolyl may optionally be substituted with        C₁₋₄alkyl; and    -   Het₂ is pyridyl;        or the combination of    -   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or        C₁₋₁₀alkyl substituted with substituent selected from the group        consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,        4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl,        pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,        C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl;        and    -   R_(4a) is C₁₋₄alkyl; and    -   R_(4b) is C₁₋₄alkyl or C₁₋₄alkyl substituted morpholinyl;        or the combination of    -   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or        C₁₋₁₀alkyl substituted with substituent selected from the group        consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,        4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl,        pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,        C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl;        and    -   aryl is phenyl optionally substituted with one or more        substituents each individually selected from the group        consisting of C₁₋₆alkyl, C₁₋₄alkoxy, cyano, nitro;        or the combination of    -   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or        C₁₋₁₀alkyl substituted with substituent selected from the group        consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,        4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl,        pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,        C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl;        and    -   aryl is phenyl optionally substituted with one or more        substituents each individually selected from the group        consisting of C₁₋₆alkyl, C₁₋₄alkoxy, cyano, nitro; and    -   R_(4a) is C₁₋₄alkyl; and    -   R_(4b) is C₁₋₄alkyl or C₁₋₄alkyl substituted morpholinyl;        or the combination of    -   R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,        hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl,        C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or        Het₁; and    -   Het₁ is a 5-membered ring system wherein one, two, three or four        ring members are heteroatoms each individually and independently        selected from the group consisting of nitrogen, oxygen and        sulfur, and wherein the remaining ring members are carbon atoms;        and, where possible, any nitrogen ring member may optionally be        substituted with C₁₋₄alkyl; any ring carbon atom may, each        individually and independently, optionally be substituted with a        substituent selected from the group consisting of C₁₋₄alkyl,        C₃₋₇cycloalkyl, halo, cyano, trifluoromethyl, cyanoC₁₋₄alkyl,        mono- or di(C₁₋₄alkyl)amino, mono- or        di(C₁₋₄alkyl)aminoC₂₋₆alkenyl, isoxazolyl, aryl,        hydroxycarbonyl, C₁₋₄alkyloxycarbonyl, oxo, thio; and wherein        the foregoing isoxazolyl may optionally be substituted with        C₁₋₄alkyl;        or the combination of    -   n is 1 or 2, more in particular wherein n is 1; and    -   R₁ is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,        C₁₋₄alkyloxycarbonyl, arylaminocarbonyl,        N-hydroxy-methanimidamidyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, Het₁ or Het₂; and    -   R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or        C₁₋₁₀alkyl substituted with substituent selected from the group        consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,        4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl,        pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,        C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl;        and    -   R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,        hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl,        C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- or        di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or        Het₁.

In one embodiment, R₁ is hydrogen, cyano, halo, aminocarbonyl,N-hydroxy-methanimidamidyl, Het₁; in particular, R₁ is hydrogen, cyano,bromo, tetrazolyl or oxadiazolyl optionally substituted with asubstituent selected from the group consisting of C₁₋₄alkyl,C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy, C₁₋₄alkoxy, amino, cyano,trifluoromethyl, hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio.

Suitable compounds are those compounds of formula (II) wherein R₃ isnitro and R₁ is hydrogen, cyano, halo, aminocarbonyl,N-hydroxy-methanimidamidyl, Het₁. More suitable compounds are thosecompounds of formula (II) wherein R₃ is nitro, R₂ is C₁₋₆alkyl and R₁ ishydrogen, cyano, bromo, tetrazolyl or oxadiazolyl optionally substitutedwith a substituent selected from the group consisting of C₁₋₄alkyl,C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy, C₁₋₄alkoxy, amino, cyano,trifluoromethyl, hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio.

In another embodiment, R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl,C₃₋₇cycloalkyl, wherein said C₁₋₁₀alkyl may be optionally substitutedwith a substituent selected from the group consisting of cyano,NR_(4a)R_(4b), pyrrolidinyl, piperidinyl, 4-(C₁₋₄alkyl)-piperazinyl,morpholinyl, aryl, imidazolyl, pyridyl, hydroxycarbonyl,N(R_(4a)R_(4b))carbonyl, C₁₋₄alkyloxycarbonyl,4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl; in particular R₂ is hydrogen,C₁₋₆alkyl, C₂₋₆alkenyl, cyclopropyl, cyclopentyl, wherein said C₁₋₆alkylmay be optionally substituted with a substituent selected from the groupconsisting of cyano, di(C₁₋₄alkyl)amino, pyrrolidinyl, piperidinyl,4-(methyl)-piperazinyl, morpholinyl, phenyl, imidazolyl, pyridyl,hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl, C₁₋₄alkyloxycarbonyl,4-(methyl)-piperazin-1-ylcarbonyl.

Suitable compounds are those compounds of formula (II) wherein R₃ isnitro and R₁ is cyano and R₂ is C₁₋₁₀alkyl, C₂₋₁₀alkenyl,C₃₋₇cycloalkyl, wherein said C₁₋₁₀alkyl may be optionally substitutedwith a substituent selected from the group consisting of cyano,NR_(4a)R_(4b), pyrrolidinyl, piperidinyl, 4-(C₁₋₄alkyl)-piperazinyl,morpholinyl, aryl, imidazolyl, pyridyl, hydroxycarbonyl,N(R_(4a)R_(4b))carbonyl, C₁₋₄alkyloxycarbonyl,4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl.

In another embodiment, R₃ is nitro, cyano, halo, C₁₋₄alkyloxy,hydroxycarbonyl, aminocarbonyl, mono- or di(C₁₋₄alkyl)methanimidamidyl,N-hydroxy-methanimidamidyl or Het₁; more in particular, R₃ is nitro,cyano, halo, C₁₋₄alkyloxy, hydroxycarbonyl, aminocarbonyl, mono- ordi(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl, oxadiazolyl,thienyl, thiazolyl, furanyl, isoxazolyl wherein each of saidoxadiazolyl, thienyl, thiazolyl, furanyl, isoxazolyl may be substitutedwith a substituent selected from the group consisting of C₁₋₄alkyl,C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy, C₁₋₄alkoxy, amino, cyano,trifluoromethyl, hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio; and whereinany of the foregoing furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl,imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl and triazolyl moieties may optionally be substituted withC₁₋₄alkyl.

Suitable compounds are those compounds of formula (II) wherein R₁ iscyano and R₃ is nitro, cyano, halo, C₁₋₄alkyloxy, hydroxycarbonyl,aminocarbonyl, mono- or di(C₁₋₄alkyl)methanimidamidyl,N-hydroxy-methanimidamidyl or Het₁. More suitable compounds are thosecompounds of formula (II) wherein R₁ is cyano, R₂ is C₁₋₆alkyl and R₃ isnitro, cyano, halo, C₁₋₄alkyloxy, hydroxycarbonyl, aminocarbonyl, mono-or di(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl,oxadiazolyl, thienyl, thiazolyl, furanyl, isoxazolyl wherein each ofsaid oxadiazolyl, thienyl, thiazolyl, furanyl, isoxazolyl may besubstituted with a substituent selected from the group consisting ofC₁₋₄alkyl, C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy, C₁₋₄alkoxy, amino,cyano, trifluoromethyl, hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio; and whereinany of the foregoing furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl,imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl and triazolyl moieties may optionally be substituted withC₁₋₄alkyl.

Another embodiment concerns compounds of formula (I) wherein

n is 1,R₁ is cyano, halo or oxadiazolyl optionally substituted with asubstituent selected from the group consisting of C₁₋₄alkyl,C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy, C₁₋₄alkoxy, amino, cyano,trifluoromethyl, hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio; and whereinany of the foregoing furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl,imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl and triazolyl moieties may optionally be substituted withC₁₋₄alkyl;R₂ is C₁₋₆alkyl, hydrogen, C₂₋₆alkenyl,R₃ is nitro, C₁₋₆alkyl optionally substituted with piperidinyl,pyrrolidinyl, N(R_(4a)R_(4b)), morpholinyl, pyridyl, cyano,4-(C₁₋₄alkyl)-piperazin-1-yl.

Yet another embodiment relates to compounds of formula (I) wherein Het₁is furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl,isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl,triazolyl, tetrazolyl, each of which individually and independently maybe optionally substituted with a substituent selected from the groupconsisting of C₁₋₄alkyl, C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy,C₁₋₄alkoxy, halo, amino, cyano, trifluoromethyl, hydroxyC₁₋₄alkyl,cyanoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio; and whereinany of the foregoing furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl,imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl and triazolyl moieties may optionally be substituted withC₁₋₄alkyl.

Preferred compounds are

-   1-(4-Nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-Methyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-Isobutyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-Allyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-Butyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-Ethyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-(2-Morpholin-4-yl-ethyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   5-Methyl-1-(4-nitro-phenyl)-1,5-dihydro-pyrido[3,2-b]indol-2-one;-   5-But-3-enyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(2-pyrrolidin-1-yl-ethyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(2-piperidin-1-yl-ethyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   5-(3-Dimethylamino-propyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   3-Bromo-5-methyl-1-(4-nitro-phenyl)-1,5-dihydro-pyrido[3,2-b]indol-2-one-   5-Methyl-1-(3-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(3-piperidin-1-yl-propyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   5-(4-Morpholin-4-yl-butyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(4-pyrrolidin-1-yl-butyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   5-[3-(4-Methyl-piperazin-1-yl)-propyl]-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-Cyanomethyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-(3-Morpholin-4-yl-propyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(4-piperidin-1-yl-butyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   5-(4-Dimethylamino-butyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-pyridin-4-ylmethyl-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   3-(5-tert-Butyl-[1,2,4]oxadiazol-3-yl)-5-methyl-1-(4-nitro-phenyl)-1,5-dihydro-pyrido[3,2-b]indol-2-one;-   5-Methyl-1-(4-nitro-phenyl)-3-(5-trifluoromethyl-[1,2,4]oxadiazol-3-yl)-1,5-dihydro-pyrido[3,2-b]indol-2-one;    and their N-oxides, salts and stereoisomers.

Most preferred compounds are

-   5-Methyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;-   5-(2-Morpholin-4-yl-ethyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(2-piperidin-1-yl-ethyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;-   1-(4-Nitro-phenyl)-2-oxo-5-(2-pyrrolidin-1-yl-ethyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;    and their N-oxides, salts and stereoisomers.

The compounds of the present invention inhibit the HIV reversetranscriptase and may also inhibit reverse transcriptases havingsimilarity to HIV reverse transcriptase. Such similarity may bedetermined using programs known in the art including BLAST. In oneembodiment, the similarity at the amino acid level is at least 25%,interestingly at least 50%, more interestingly at least 75%. In anotherembodiment, the similarity at the amino acid level at the bindingpocket, for the compounds of the present invention, is at least 75%, inparticular at least 90% as compared to HIV reverse transcriptase.Compounds of the present invention have been tested in otherlentiviruses besides HIV-1, such as, for example, SIV and HIV-2.

The compounds of the present invention have a good selectivity asmeasured by the ratio between EC₅₀ and CC₅₀ as described and exemplifiedin the antiviral analysis example. The compounds of the presentinvention have also a favorable specificity. There exists a highdissociation between the activity on lentiviruses versus otherretroviridae, such as MLV, and versus non-viral pathogens. For instance,compound 2 had an EC₅₀ value of more than 32 μM for Mycobacterium b.,Plasmodium f., Trypanosoma b. and Trypanosoma c. whereas the EC₅₀ valuefor wild-type HIV was well below 100 nM.

The standard of “sensitivity” or alternatively “resistance” of a HIVreverse transcriptase enzyme to a drug is set by the commerciallyavailable HIV reverse transcriptase inhibitors. Existing commercial HIVreverse transcriptase inhibitors including efavirenz, nevirapine anddelavirdine may loose effectivity over time against a population of HIVvirus in a patient. The reason being that under pressure of the presenceof a particular HIV reverse transcriptase inhibitor, the existingpopulation of HIV virus, usually mainly wild type HIV reversetranscriptase enzyme, mutates into different mutants which are far lesssensitive to that same HIV reverse transcriptase inhibitor. If thisphenomenon occurs, one talks about resistant mutants. If those mutantsare not only resistant to that one particular HIV reverse transcriptaseinhibitor, but also to multiple other commercially available HIV reversetranscriptase inhibitors, one talks about multi-drug resistant HIVreverse transcriptase. One way of expressing the resistance of a mutantto a particular HIV reverse transcriptase inhibitor is making the ratiobetween the EC₅₀ of said HIV reverse transcriptase inhibitor againstmutant HIV reverse transcriptase over EC₅₀ of said HIV reversetranscriptase inhibitor against wild type HIV reverse transcriptase.Said ratio is also called fold change in resistance (FR). The EC₅₀ valuerepresents the amount of the compound required to protect 50% of thecells from the cytopathogenic effect of the virus.

Many of the mutants occurring in the clinic have a fold resistance of100 or more against the commercially available HIV reverse transcriptaseinhibitors, like nevirapine, efavirenz, delavirdine. Clinically relevantmutants of the HIV reverse transcriptase enzyme may be characterized bya mutation at codon position 100, 103 and 181. As used herein a codonposition means a position of an amino acid in a protein sequence.Mutations at positions 100, 103 and 181 relate to non-nucleoside RTinhibitors (D'Aquila et al. Topics in HIV medicine, 2002, 10, 11-15).Examples of such clinical relevant mutant HIV reverse transcriptases arelisted in Table 1.

TABLE 1 List of mutations present in reverse transcriptase of the HIVstrains used. A Y181C B K103N C L100I; K103N D L100I; K103N E F227C FY188L G V106A, F227L H K103N, Y181C I K101E, K103N J I31L, L100I, K103N,E138G, Y181C, L214F K K2OR, E28K, M41L, E44A, D67N, L74I, K103N, V118I,D123N, S162C, Y181C, G196K, Q207E, L210W, L214F, T215Y, K219N, P225H,D250E, P272A, R277K, I293V, P297K, K311R, R358K, T376A, E399D, T400L

An interesting group of compounds are those compounds of formula (I)having a fold resistance ranging between 0.01 and 100 against at leastone mutant HIV reverse transcriptase, suitably ranging between 0.1 and100, more suitably ranging between 0.1 and 50, and even more suitablyranging between 0.1 and 30. Of particular interest are the compounds offormula (I) showing a fold resistance against at least one mutant HIVreverse transcriptase ranging between 0.1 and 20, and even moreinteresting are those compounds of formula (I) showing a fold resistanceagainst at least one mutant HIV reverse transcriptase ranging between0.1 and 10.

An interesting group of compounds are those compounds of formula (I)having a fold resistance, determined according to the methods hereindescribed, in the range of 0.01 to 100 against HIV species having atleast one mutation in the amino acid sequence of HIV reversetranscriptase as compared to the wild type sequence (genbank accessione.g. M38432, K03455, gi 327742) at a position selected from 100, 103 and181; in particular at least two mutations selected from the positions100, 103 and 181. Even more interesting are those compounds within saidinteresting group of compounds having a fold resistance in the range of0.1 to 100, in particular in the range 0.1 to 50, more in particular inthe range 0.1 to 30. Most interesting are those compounds within saidinteresting group of compounds having a fold resistance in the range of0.1 and 20, especially ranging between 0.1 and 10.

In one embodiment, the compounds of the present invention show a foldresistance in the ranges mentioned just above against at least oneclinically relevant mutant HIV reverse transcriptases.

A particular group of compounds are those compounds of formula (I)having an IC₅₀ of 1 μM or lower, suitably an IC₅₀ of 100 nM or lowervis-à-vis the wild type virus upon in vitro screening according to themethods described herein.

The ability of the present compounds to inhibit HIV-1, HIV-2, SIV andHIV viruses with reverse transcriptase (RT) enzymes having mutated underpressure of the currently known RT inhibitors, together with the absenceof cross resistance with currently known RT inhibitors indicate that thepresent compounds bind differently to the RT enzyme when compared to theknown NNRTIs and NRTIs. With respect to the cross resistance, a studywith more than 8000 viruses showed that the calculated correlationcoefficient between the present compound 2 and known NRTIs, such as forexample 3TC, abacavir, AZT, D4T, DDC, DDI, was in all cases lower than0.28 with an exception of 3TC where the correlation coefficient wasabout 0.63. The correlation coefficient between the present compound 2and known NNRTIs such as for example capravirine, delavirdine,nevirapine and efavirenz was in all cases about 0.13 or lower.

The compounds of the present invention show antiretroviral properties,in particular against Human Immunodeficiency Virus (HIV), which is theaetiological agent of Acquired Immune Deficiency Syndrome (AIDS) inhumans. The HIV virus preferentially infects CD4 receptor containingcells such as human T4 cells and destroys them or changes their normalfunction, particularly the coordination of the immune system. As aresult, an infected patient has an ever-decreasing number of T4 cells,which moreover behave abnormally. Hence, the immunological defensesystem is unable to combat infections and/or neoplasms and the HIVinfected subject usually dies by opportunistic infections such aspneumonia, or by cancers. Other diseases associated with HIV infectioninclude thrombocytopenia, Kaposi's sarcoma and infection of the centralnervous system characterized by progressive demyelination, resulting indementia and symptoms such as, progressive dysarthria, ataxia anddisorientation. HIV infection further has also been associated withperipheral neuropathy, progressive generalized lymphadenopathy (PGL) andAIDS-related complex (ARC). The HIV virus also infects CD8-receptorcontaining cells. Other target cells for HIV virus include microglia,dendritic cells, B-cells and macrophages.

Due to their favourable pharmacological properties, particularly theiractivity against HIV reverse transcriptase enzymes, the compounds of thepresent invention or any subgroup thereof may be used as medicinesagainst above-mentioned diseases or in the prophylaxis thereof. Said useas a medicine or method of treatment comprises the systemicadministration to HIV-infected subjects of an amount effective to combatthe conditions associated with HIV.

In one embodiment, the present invention concerns the use of a compoundof formula (I) or any subgroup thereof in the manufacture of amedicament useful for preventing, treating or combating infection ordisease associated with HIV infection.

In another embodiment, the present invention concerns the use of acompound of formula (I) or any subgroup thereof in the manufacture of amedicament useful for inhibiting replication of a HIV virus, inparticular a HIV virus having a mutant HIV reverse transcriptase, morein particular a multi-drug resistant mutant HIV reverse transcriptase.

In yet another embodiment, the present invention relates to the use of acompound of formula (I) or any subgroup thereof in the manufacture of amedicament useful for preventing, treating or combating a diseaseassociated with HIV viral infection wherein the reverse transcriptase ofthe HIV virus is mutant, in particular a multi-drug resistant mutant HIVreverse transcriptase.

The compounds of formula (I) or any subgroup thereof are also useful ina method for preventing, treating or combating infection or diseaseassociated with HIV infection in a mammal, comprising administering tosaid mammal an effective amount of a compound of formula (I) or anysubgroup thereof.

In another aspect, the compounds of formula (I) or any subgroup thereofare useful in a method for preventing, treating or combating infectionor disease associated with infection of a mammal with a mutant HIVvirus, comprising administering to said mammal an effective amount of acompound of formula (I) or any subgroup thereof.

In another aspect, the compounds of formula (I) or any subgroup thereofare useful in a method for preventing, treating or combating infectionor disease associated with infection of a mammal with a multidrug-resistant HIV virus, comprising administering to said mammal aneffective amount of a compound of formula (I) or any subgroup thereof.

In yet another aspect, the compounds of formula (I) or any subgroupthereof are useful in a method for inhibiting replication of a HIVvirus, in particular a HIV virus having a mutant HIV reversetranscriptase, more in particular a multi-drug resistant mutant HIVreverse transcriptase, comprising administering to a mammal in needthereof an effective amount of a compound of formula (I) or any subgroupthereof.

Most interestingly, a mammal as mentioned in the present methods is ahuman being.

The compounds of the present invention may also find use in inhibitingex vivo samples containing HIV or expected to be exposed to HIV. Hence,the present compounds may be used to inhibit HIV present in a body fluidsample that contains or is suspected to contain or be exposed to HIV.

Particular reaction procedures to make the present compounds aredescribed below. In the preparations described below, the reactionproducts may be isolated from the medium and, if necessary, furtherpurified according to methodologies generally known in the art such as,for example, extraction, crystallization, trituration andchromatography.

Route 1: Synthesis of Present Compounds Wherein R₃ is Nitro, Cyano(R_(3′))

The synthesis of compounds (a-6) and (a-7) conveniently starts from1-C₁₋₆alkylcarbonyl-3-hydroxyindole (a-1). Condensation of (a-1) withnitroaniline at elevated temperatures and in a suitable solvent such asacetic acid, toluene, benzene, an alcohol and the like, yields3-((nitrophenyl)amino)indole (a-2). In one embodiment, the nitroanilineis para-nitroaniline. Intermediate (a-2) can then be deacylated with abase, such as for example triethylamine, sodiumhydroxide, sodiumacetate,potassiumacetate or potassiumcarbonate and the like, in a suitablesolvent, such as for example methanol or ethanol, and at elevatedtemperature, yielding intermediate (a-3). Formylation of intermediate(a-3) results in indole aldehyde (a-4) and may be performed by employingfor instance a Vilsmeier reaction. Condensation of intermediate (a-4)results in intermediate (a-5). In one embodiment, said condensation maybe performed using a base such as for example triethylamine,sodiumacetate, potassiumacetate, piperidine and the like, in a widevariety of solvents, and with a oxycarbonylmethylene reagent of formulaCHR₁P₂—C(═O)—OP₁, wherein P₁ represents C₁₋₆alkyl, C₆₋₁₄aryl orC₆₋₁₄aryl-C₁₋₆alkyl and P₂ represents a hydrogen, a carboxylic ester, aphosphonium salt or a phosphonate ester. Suitably, the reagent is offormula CH₂R₁, —C(═O)—OP₁, wherein P₁ is C₁₋₆alkyl. Subsequentintramolecular cyclisation of intermediate (a-5) at elevated temperatureand in a solvent like ethyleneglycol, dioxane, N,N-dimethylformamide,dimethylsulfoxide, glyme, diglyme and the like, yields compound (a-6)which may be transformed into a compound of formula (a-7) using anN-alkylation reaction with an intermediate of formula R₂—X wherein X isa leaving group. Examples of such leaving groups include sulfonates suchas tosylate, mesylate; acetates; halogens such bromide, iodide, chlorideand fluoride.

Other transformations from the compounds of formula (a-6) and (a-7) maybe performed using art-known transformation techniques. For instance,the compounds of formula (a-6) or (a-7) wherein R₃ is nitro may bereduced to R₃ being amino, and may then be further derivatized. Furtherexamples of transformation reactions are given in example schemes A2through A15 in the experimental part.

The order of the mentioned steps in said process scheme A may bedifferent. For instance the formylation may be performed prior todeacylation.

Oxycarbonylmethylene reagents of formula CHR₁P₂—C(═O)—OP₁ wherein P₂represents a carboxylic ester are for instance dicarboxylic esters offormula P₁O—C(═O)—CHP₂—C(═O)—OP₁ Oxycarbonylmethylene reagents offormula CHR₁P₂—C(═O)—OP₁ wherein P₂ represents a phosphonium salt mayfor instance have the formula (P₁)₃P═CR₁, —C(═O)—OP₁.Oxycarbonylmethylene reagents of formula CHR₁P₂—C(═O)—OP₁ wherein P₂represents (P₁O)₂P(═O)— may for instance have the formula(P₁O)₂P(═O)—CHR₁—C(═O)—OP₁.

Route 2: Synthesis of Present Compounds Wherein R₃ is Halo orC₁₋₆alkyloxy (R_(3″))

The intermediate (b-1) may be reacted with a reagent of formula (I) in asuitable solvent such as for example toluene, acetic acid, an alcoholand the like, in the presence of a catalyst such as for examplep-toluenesulfonic acid to yield an intermediate of formula (b-2).Elevated temperatures and stirring may enhance the reaction. Saidintermediate (b-2) may then be reacted with chloroacetyl chloride or afunctional derivative thereof, suitable at elevated temperature, toyield an intermediate of formula (b-3). Said intermediate of formula(b-3) may be deprotected using a suitable base such as trietylamine,sodiumacetate, potassium acetate, sodiumhydroxide, potassiumhydroxide,potassiumcarbonate and the like, in a solvent like methanol or ethanol.Stirring and heating may enhance the reaction. The thus formedintermediate of formula (b-4) may be cyclised by first usingpotassiumcyanide or tetrabutylammoniumcyanide, and subsequentlysubmitting the intermediate to a Vilsmeier formylation using POCl₃ inN,N-dimethylformamide to form compound (b-5) which belongs to the classof compounds of formula (I).

Said compound (b-5) may further be transformed into other compounds offormula (I) using art-known transformation reactions. Of which severalare described in the exemplary scheme in the experimental part of thedescription. For example where R₃ is Br, Br may be transformed into aHeterocyclic ring using Heterocyclic borates and palladium.

Route 3: Synthesis of Present Compounds Wherein R₃ is Cyano, Nitro orC₁₋₆alkyloxycarbonyl (R_(3′″))

The intermediate (c-1) may be reacted with a reagent of formula (I) in asuitable solvent such as for example toluene, acetic acid, an alcoholand the like, in the presence of a catalyst such as for examplep-toluenesulfonic acid to yield an intermediate of formula (c-2).Elevated temperatures and stirring may enhance the reaction. Saidintermediate (c-2) may then be reacted with acetic anhydride in thepresence of a catalyst such as for example pyridine ordimethylaminopyridine or the like, suitable at elevated temperature, toyield an intermediate of formula (c-3). The thus formed intermediate offormula (c-3) may be reacted using a Vilsmeier reaction with POCl₃ inN,N-dimethylformamide to form intermediate (c-4) which in turn can befurther cyclised to compound (c-5) in an aqueous acidic environment.

Said compound (c-5), belonging to the class of compounds of formula (I),may further be transformed into other compounds of formula (I) usingart-known transformation reactions. Of which several are described inthe exemplary scheme in the experimental part of the description. Forexample R₃ being C₁₋₆alkyloxycarbonyl may be transformed to theequivalent carboxylic acid or amide. Also R₃ being cyano may betransformed to a heterocycle such as a tetrazolyl, oxadiazolyl,thiazolyl etc.

Route 4: Synthesis of Present Compounds Wherein R₁ is Hydrogen

An intermediate of formula (d-1) can be reacted with a C₁₋₆alkyliodideor C₁₋₆alkyl-sulfate in the presence of a base such as for examplepotassium carbonate, potassiumhydroxide, sodiumhydroxide and the like,in a reaction-inert solvent such as for example N,N-dimethylformamide,acetonitrile, acetone, ethanol, water and the like. Stirring may enhancethe reaction rate. The thus formed intermediate of formula (d-2) canthen be further reacted with hydroxylamine in a solvent like water,ethanol or a mixture thereof and in the presence of a base likesodiumacetate, potassium acetate, potassium carbonate, sodiumacetate andthe like, to form an intermediate of formula (d-3). Upon heating andbringing the intermediate of formula (d-3) in an acidic aqueousenvironment, an intermediate of formula (d-4) is formed. Saidintermediate can then be subjected to an intramolecular cyclisation inthe presence of POCl₃ in N,N-dimethylformamide. Cooling the reactionmixture may be advantageous. The thus formed intermediate of formula(d-5) can be treated with Zinc in an acidic aqueous environment such asHCl to form an intermediate of formula (d-6). The N-oxide can beprepared using metachloroperbenzoic acid, waterperoxide,tert-butylhydroperoxide and the like, or a functional equivalent thereofin a solvent such as, for example, dichloromethane, chloroform, analcohol, toluene or the like, and employing elevated temperatures. SaidN-oxide of formula (d-7) can be further reacted, suitably at elevatedtemperature, with acetic anhydride to form the intermediate of formula(d-8). Finally, a boronic acid of formula (II) can be used to preparethe compounds of formula (I) equivalent to the formula (d-9). Saidreaction step involves the use of copper(II) acetate or an equivalentthereof in a solvent such as for example N,N-dimethylformamide,dichloromethane, toluene, an alcohol, chloroform and the like. Suitablea quencher like pyridine may be added to the reaction mixture. Elevatingthe temperature may enhance the reaction.

Route 5: Synthesis of Present Compounds with Different R2

The compounds of formula (I) wherein R₂ is hydrogen can be transformedinto compounds of formula (I) wherein R₂ is different from hydrogen. Forthis purpose, reagents like R₂-Cl wherein Cl is a leaving group can beused in the presence of a base such as sodium hydride or potassiumcarbonate, potassium hydroxide, sodium-hydroxide and the like. Othersuitable leaving groups may also be employed such as for examplesulfonates such as tosylate, mesylate; acetates; halogens such bromide,iodide, chloride and fluoride. The reaction procedure can be used forintroducing for instance

-   -   methyl, ethyl, cyclopropyl, butyl, isobytul, isopentyl,        cyclopentyl;    -   allyl, homoallyl, benzyl;    -   4-pyridinylmethyl, 3-pyridinylmethyl, 2-pyridinylmethyl;    -   4-imidazolyl-ethyl;    -   dimethylamino(-ethyl, -propyl, -butyl), piperidino(-ethyl,        -propyl, -butyl), pyrrolidino(-ethyl, -propyl, -butyl),        N-methyl-piperazino(-ethyl, -propyl, -butyl),        pyrrolidino(-ethyl, -propyl, -butyl);    -   cyanomethyl, cyanoethyl;    -   alkylation with ethyl bromoacetate and further conversion of the        ester to carboxylic acid and amides;

Other transformation reactions not specifically mentioned above may alsobe performed. Some examples thereof are mentioned in the exemplaryschemes in the experimental part of the description.

The compounds of formula (I) may also be converted to the correspondingN-oxide forms following art-known procedures for converting a trivalentnitrogen into its N-oxide form. Said N-oxidation reaction may generallybe carried out by reacting the starting material of formula (I) with anappropriate organic or inorganic peroxide. Appropriate inorganicperoxides comprise, for example, hydrogen peroxide, alkali metal orearth alkaline metal peroxides, e.g. sodium peroxide, potassiumperoxide; appropriate organic peroxides may comprise peroxy acids suchas, for example, benzenecarboperoxoic acid or halo substitutedbenzenecarboperoxoic acid, e.g. 3-chloro-benzenecarboperoxoic acid,peroxoalkanoic acids, e.g. peroxoacetic acid, alkylhydroperoxides, e.g.tert-butyl hydroperoxide. Suitable solvents are, for example, water,lower alkanols, e.g. ethanol and the like, hydrocarbons, e.g. toluene,ketones, e.g. 2-butanone, halogenated hydrocarbons, e.g.dichloromethane, and mixtures of such solvents.

A basic nitrogen occurring in the present compounds can be quaternizedwith any agent known to those of ordinary skill in the art including,for instance, lower alkyl halides, dialkyl sulfates, long chain halidesand aralkyl halides according to art-known procedures.

The present compounds can thus be used in animals, preferably inmammals, and in particular in humans as pharmaceuticals per se, inmixtures with one another or in the form of pharmaceutical preparations.

Consequently, the present invention relates to pharmaceuticalpreparations that as active constituents contain an effective dose of atleast one of the compounds of formula (I) in addition to customarypharmaceutically innocuous excipients and auxiliaries. Thepharmaceutical preparations normally contain 0.1 to 90% by weight of acompound of formula (I). The pharmaceutical preparations can be preparedin a manner known per se to one of skill in the art. For this purpose,at least one of a compound of formula (I), together with one or moresolid or liquid pharmaceutical excipients and/or auxiliaries and, ifdesired, in combination with other pharmaceutical active compounds, arebrought into a suitable administration form or dosage form which canthen be used as a pharmaceutical in human medicine or veterinarymedicine.

Pharmaceuticals which contain a compound according to the invention canbe administered orally, parenterally, e.g., intravenously, rectally, byinhalation, or topically, the preferred administration being dependenton the individual case, e.g., the particular course of the disorder tobe treated. Oral administration is preferred.

The person skilled in the art is familiar on the basis of his expertknowledge with the auxiliaries that are suitable for the desiredpharmaceutical formulation. Beside solvents, gel-forming agents,suppository bases, tablet auxiliaries and other active compoundcarriers, antioxidants, dispersants, emulsifiers, antifoams, flavorcorrigents, preservatives, solubilizers, agents for achieving a depoteffect, buffer substances or colorants are also useful.

Also, the combination of an antiretroviral compound and a compound ofthe present invention can be used as a medicine. Thus, the presentinvention also relates to a product containing (a) a compound of thepresent invention, and (b) another antiretroviral compound, as acombined preparation for simultaneous, separate or sequential use intreatment of retroviral infections such as HIV infection, in particular,in the treatment of infections with multi-drug resistant retroviruses.Thus, to prevent, combat or treat HIV infections and the diseaseassociated with HIV infections, such as Acquired ImmunodeficiencySyndrome (AIDS) or AIDS Related Complex (ARC), the compounds of thisinvention may be co-administered in combination with for instance,binding inhibitors, such as, for example, dextran sulfate, suramine,polyanions, soluble CD4, PRO-542, BMS-806; fusion inhibitors, such as,for example, T20, T1249, RPR 103611, YK-FH312, IC 9564, 5-helix,D-peptide ADS-J1; co-receptor binding inhibitors, such as, for example,AMD 3100, AMD-3465, AMD7049, AMD3451 (Bicyclams), TAK 779, T-22,ALX40-4C; SHC-C(SCH351125), SHC-D, PRO-140, RPR103611; RT inhibitors,such as, for example, foscarnet and prodrugs; nucleoside RTIs, such as,for example, AZT, 3TC, DDC, DDI, D4T, Abacavir, FTC, DAPD (Amdoxovir),dOTC (BCH-10652), fozivudine, DPC 817; nucleotide RTIs, such as, forexample, PMEA, PMPA (tenofovir); NNRTIs, such as, for example,nevirapine, delavirdine, efavirenz, 8 and 9-Cl TIBO (tivirapine),loviride, TMC-125, dapivirine, MKC-442, UC 781, UC 782, Capravirine,QM96521, GW420867X, DPC 961, DPC963, DPC082, DPC083, calanolide A,SJ-3366, TSAO, 4″-deaminated TSAO, MV150, MV026048, PNU-142721; RNAse Hinhibitors, such as, for example, SP1093V, PD126338; TAT inhibitors,such as, for example, RO-5-3335, K12, K37; integrase inhibitors, suchas, for example, L 708906, L 731988, S-1360; protease inhibitors, suchas, for example, amprenavir and fosamprenavir, ritonavir, nelfinavir,saquinavir, indinavir, lopinavir, palinavir, BMS 186316, atazanavir, DPC681, DPC 684, tipranavir, AG1776, mozenavir, DMP-323, GS3333, KNI-413,KNI-272, L754394, L756425, LG-71350, PD161374, PD173606, PD177298,PD178390, PD 178392, PNU 140135, TMC-114, maslinic acid, U-140690;glycosylation inhibitors, such as, for example, castanospermine,deoxynojirimycin; entry inhibitors CGP64222.

The combination may provide a synergistic effect, whereby viralinfectivity and its associated symptoms may be prevented, substantiallyreduced, or eliminated completely.

The compounds of the present invention may also be administered incombination with immunomodulators (e.g., bropirimine, anti-human alphainterferon antibody, IL-2, methionine enkephalin, interferon alpha, andnaltrexone) with antibiotics (e.g., pentamidine isothiorate) cytokines(e.g. Th2), modulators of cytokines, chemokines or modulators ofchemokines, chemokine receptors (e.g. CCR5, CXCR4), modulators chemokinereceptors, or hormones (e.g. growth hormone) to ameliorate, combat, oreliminate HIV infection and its symptoms. Such combination therapy indifferent formulations, may be administered simultaneously, sequentiallyor independently of each other. Alternatively, such combination may beadministered as a single formulation, whereby the active ingredients arereleased from the formulation simultaneously or separately.

The compounds of the present invention may also be administered incombination with modulators of the metabolization following applicationof the drug to an individual. These modulators include compounds thatinterfere with the metabolization at cytochromes, such as cytochromeP450. It is known that several isoenzymes exist of cytochrome P450, oneof which is cytochrome P450 3A4. Ritonavir is an example of a modulatorof metabolization via cytochrome P450. Such combination therapy indifferent formulations, may be administered simultaneously, sequentiallyor independently of each other. Alternatively, such combination may beadministered as a single formulation, whereby the active ingredients arereleased from the formulation simultaneously or separately. Suchmodulator may be administered at the same or different ratio as thecompound of the present invention. Preferably, the weight ratio of suchmodulator vis-à-vis the compound of the present invention(modulator:compound of the present invention) is 1:1 or lower, morepreferable the ratio is 1:3 or lower, suitably the ratio is 1:10 orlower, more suitably the ratio is 1:30 or lower.

For an oral administration form, compounds of the present invention aremixed with suitable additives, such as excipients, stabilizers or inertdiluents, and brought by means of the customary methods into thesuitable administration forms, such as tablets, coated tablets, hardcapsules, aqueous, alcoholic, or oily solutions. Examples of suitableinert carriers are gum ilute, magnesia, magnesium carbonate, potassiumphosphate, lactose, glucose, or starch, in particular, corn starch. Inthis case the preparation can be carried out both as dry and as moistgranules. Suitable oily excipients or solvents are vegetable or animaloils, such as sunflower oil or cod liver oil. Suitable solvents foraqueous or alcoholic solutions are water, ethanol, sugar solutions, ormixtures thereof. Polyethylene glycols and polypropylene glycols arealso useful as further auxiliaries for other administration forms.

For subcutaneous or intravenous administration, the active compounds, ifdesired with the substances customary therefore such as solubilizers,emulsifiers or further auxiliaries, are brought into solution,suspension, or emulsion. The compounds of formula (I) can also belyophilized and the lyophilizates obtained used, for example, for theproduction of injection or infusion preparations. Suitable solvents are,for example, water, physiological saline solution or alcohols, e.g.ethanol, propanol, glycerol, in addition also sugar solutions such asglucose or mannitol solutions, or alternatively mixtures of the varioussolvents mentioned.

Suitable pharmaceutical formulations for administration in the form ofaerosols or sprays are, for example, solutions, suspensions or emulsionsof the compounds of formula (I) or their physiologically tolerable saltsin a pharmaceutically acceptable solvent, such as ethanol or water, or amixture of such solvents. If required, the formulation can alsoadditionally contain other pharmaceutical auxiliaries such assurfactants, emulsifiers and stabilizers as well as a propellant. Such apreparation customarily contains the active compound in a concentrationfrom approximately 0.1 to 50%, in particular from approximately 0.3 to3% by weight.

In order to enhance the solubility and/or the stability of the compoundsof formula (I) in pharmaceutical compositions, it can be advantageous toemploy α-, β- or γ-cyclo-dextrins or their derivatives. Also co-solventssuch as alcohols may improve the solubility and/or the stability of thecompounds of formula (I) in pharmaceutical compositions. In thepreparation of aqueous compositions, addition salts of the subjectcompounds are obviously more suitable due to their increased watersolubility.

Appropriate cyclodextrins are α-, β- or γ-cyclodextrins (CDs) or ethersand mixed ethers thereof wherein one or more of the hydroxy groups ofthe anhydroglucose units of the cyclodextrin are substituted withC₁₋₆alkyl, particularly methyl, ethyl or isopropyl, e.g. randomlymethylated β-CD; hydroxyC₁₋₆alkyl, particularly hydroxyethyl,hydroxypropyl or hydroxybutyl; carboxyC₁₋₆alkyl, particularlycarboxymethyl or carboxyethyl; C₁₋₆alkylcarbonyl, particularly acetyl;C₁₋₆alkyloxycarbonylC₁₋₆alkyl or carboxyC₁₋₆alkyloxyC₁₋₆alkyl,particularly carboxymethoxypropyl or carboxyethoxy-propyl;C₁₋₆alkylcarbonyloxyC₁₋₆alkyl, particularly 2-acetyloxypropyl.Especially noteworthy as complexants and/or solubilizers are β-CD,randomly methylated β-CD, 2,6-dimethyl-β-CD, 2-hydroxyethyl-β-CD,2-hydroxyethyl-γ-CD, 2-hydroxypropyl-γ-CD and(2-carboxymethoxy)propyl-β-CD, and in particular 2-hydroxypropyl-β-CD(2-HP-β-CD).

The term mixed ether denotes cyclodextrin derivatives wherein at leasttwo cyclodextrin hydroxy groups are etherified with different groupssuch as, for example, hydroxy-propyl and hydroxyethyl.

An interesting way of formulating the present compounds in combinationwith a cyclodextrin or a derivative thereof has been described inEP-A-721,331. Although the formulations described therein are withantifungal active ingredients, they are equally interesting forformulating the compounds of the present invention. The formulationsdescribed therein are particularly suitable for oral administration andcomprise an antifungal as active ingredient, a sufficient amount of acyclodextrin or a derivative thereof as a solubilizer, an aqueous acidicmedium as bulk liquid carrier and an alcoholic co-solvent that greatlysimplifies the preparation of the composition. Said formulations mayalso be rendered more palatable by adding pharmaceutically acceptablesweeteners and/or flavours.

Other convenient ways to enhance the solubility of the compounds of thepresent invention in pharmaceutical compositions are described in WO94/05263, WO 98/42318, EP-A-499,299 and WO 97/44014, all incorporatedherein by reference.

More in particular, the present compounds may be formulated in apharmaceutical composition comprising a therapeutically effective amountof particles consisting of a solid dispersion comprising (a) a compoundof formula (I), and (b) one or more pharmaceutically acceptablewater-soluble polymers.

The term “a solid dispersion” defines a system in a solid state (asopposed to a liquid or gaseous state) comprising at least twocomponents, wherein one component is dispersed more or less evenlythroughout the other component or components. When said dispersion ofthe components is such that the system is chemically and physicallyuniform or homogenous throughout or consists of one phase as defined inthermo-dynamics, such a solid dispersion is referred to as “a solidsolution”. Solid solutions are preferred physical systems because thecomponents therein are usually readily bioavailable to the organisms towhich they are administered.

The term “a solid dispersion” also comprises dispersions which are lesshomogenous throughout than solid solutions. Such dispersions are notchemically and physically uniform throughout or comprise more than onephase.

The water-soluble polymer in the particles is conveniently a polymerthat has an apparent viscosity of 1 to 100 mPa·s when dissolved in a 2%aqueous solution at 20° C. solution.

Preferred water-soluble polymers are hydroxypropyl methylcelluloses orHPMC. HPMC having a methoxy degree of substitution from about 0.8 toabout 2.5 and a hydroxypropyl molar substitution from about 0.05 toabout 3.0 are generally water soluble. Methoxy degree of substitutionrefers to the average number of methyl ether groups present peranhydroglucose unit of the cellulose molecule. Hydroxy-propyl molarsubstitution refers to the average number of moles of propylene oxidewhich have reacted with each anhydroglucose unit of the cellulosemolecule.

The particles as defined hereinabove can be prepared by first preparinga solid dispersion of the components, and then optionally grinding ormilling that dispersion. Various techniques exist for preparing soliddispersions including melt-extrusion, spray-drying andsolution-evaporation, melt-extrusion being preferred.

It may further be convenient to formulate the present compounds in theform of nanoparticles which have a surface modifier adsorbed on thesurface thereof in an amount sufficient to maintain an effective averageparticle size of less than 1000 nm. Useful surface modifiers arebelieved to include those that physically adhere to the surface of theantiretroviral agent but do not chemically bond to the antiretroviralagent.

Suitable surface modifiers can preferably be selected from known organicand inorganic pharmaceutical excipients. Such excipients include variouspolymers, low molecular weight oligomers, natural products andsurfactants. Preferred surface modifiers include iluted c and anionicsurfactants.

Yet another interesting way of formulating the present compoundsinvolves a pharmaceutical composition whereby the present compounds areincorporated in hydrophilic polymers and applying this mixture as a coatfilm over many small beads, thus yielding a composition with goodbioavailability which can conveniently be manufactured and which issuitable for preparing pharmaceutical dosage forms for oraladministration.

Said beads comprise (a) a central, rounded or spherical core, (b) acoating film of a hydrophilic polymer and an antiretroviral agent and(c) a seal-coating polymer layer.

Materials suitable for use as cores in the beads are manifold, providedthat said materials are pharmaceutically acceptable and have appropriatedimensions and firmness. Examples of such materials are polymers,inorganic substances, organic substances, and saccharides andderivatives thereof.

The route of administration may depend on the condition of the subject,co-medication and the like.

Another aspect of the present invention concerns a kit or containercomprising a compound of formula (I) in an amount effective for use as astandard or reagent in a test or assay for determining the ability of apotential pharmaceutical to inhibit HIV reverse transcriptase, HIVgrowth, or both. This aspect of the invention may find its use inpharmaceutical research programs.

The compounds of the present invention can be used in phenotypicresistance monitoring assays, such as known recombinant assays, in theclinical management of resistance developing diseases such as HIV. Aparticularly useful resistance monitoring system is a recombinant assayknown as the Antivirogram®. The Antivirogram® is a highly automated,high throughput, second generation, recombinant assay that can measuresusceptibility, especially viral susceptibility, to the compounds of thepresent invention. (Hertogs K et al. Antimicrob Agents Chemother, 1998;42(2):269-276, incorporated by reference).

Interestingly, the compounds of the present invention may comprisechemically reactive moieties capable of forming covalent bonds tolocalized sites such that said compound have increased tissue retentionand half-lives. The term “chemically reactive group” as used hereinrefers to chemical groups capable of forming a covalent bond. Reactivegroups will generally be stable in an aqueous environment and willusually be carboxy, phosphoryl, or convenient acyl group, either as anester or a mixed anhydride, or an imidate, or a maleimidate therebycapable of forming a covalent bond with functionalities such as an aminogroup, a hydroxy or a thiol at the target site on for example bloodcomponents such as albumine. The compounds of the present invention maybe linked to maleimide or derivatives thereof to form conjugates.

The dose of the present compounds or of the physiologically tolerablesalt(s) thereof to be administered depends on the individual case and,as customary, is to be adapted to the conditions of the individual casefor an optimum effect. Thus it depends, of course, on the frequency ofadministration and on the potency and duration of action of thecompounds employed in each case for therapy or prophylaxis, but also onthe nature and severity of the infection and symptoms, and on the sex,age, weight co-medication and individual responsiveness of the human oranimal to be treated and on whether the therapy is acute orprophylactic. Customarily, the daily dose of a compound of formula (I)in the case of administration to a patient approximately 75 kg in weightis 1 mg to 3 g, preferably 3 mg to 1 g, more preferably, 5 mg to 0.5 g.The dose can be administered in the form of an individual dose, ordivided into several, e.g. two, three, or four, individual doses.

LEGENDS TO THE FIGURES

FIG. 1: Time of addition experiment.

Y-axis: normalized virus production in %. X-axis: time of addition, inhours, of the compounds under investigation, following infection of thecells with HIV-LAI.

FIG. 2: In vitro inhibition of reverse transcriptase.

Y-axis: percentage inhibition of HIV reverse transcriptase compared tocontrol. X-axis: amount of compound added to wells in micromolar.

EXPERIMENTAL PART Preparation of the Compounds of Formula (I) and theirIntermediates

The synthesis of compounds (f) and (g) started from the commerciallyavailable 1-acetyl-3-hydroxyindole (a). Condensation of intermediate (a)with 4-nitroaniline, under refluxing conditions in acetic acid, yielded3-((4-nitrophenyl)amino)indole (b) (Valezheva et al.; Chem. Heterocycl.Compd. (Engl. Transl.); 14; 1978; 757,759,760; Khim. Geterotsikl.Soedin.; 14; 1978; 939). Deacylation of intermediate (b) withtriethylamine in refluxing methanol and formylation of intermediate (c)using phosphorus oxychloride in dimethylformamide resulted inintermediate (d) (Ryabova, S. Yu.; Tugusheva, N. Z.; Alekseeva, L. M.;Granik, V. G.; Pharm. Chem. J. (Engl. Transl.); EN; 30; 7; 1996;472-477; Khim. Farm. Zh.; RU; 30; 7; 1996; 42-46). Knoevenagelcondensation of intermediate (d) with ethyl cyanoacetate in the presenceof a catalytic amount of triethylamine and subsequent intramolecularcyclisation of intermediate (e) under reflux in 1,2-ethanediol, yieldedcompound (1)(1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile)(Ryabova, S. Yu.; Alekseeva, L. M.; Granik, B. G.; Chem. Heterocycl.Compd. (Engl. Translat.)36; 3; 2000; 301-306; Khim. Geterotsikl.Soedin.; RU; 3; 2000; 362-367). N-methylation using methyl iodide led tocompound (2)(5-methyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile).

More in particular, to a mixture of N-acetyl-3-hydroxyindole (a) (0.114mol, 20 g) in acetic acid (150 ml), was added 4-nitroaniline (1.5equiv., 0.171 mol, 23.65 g). The mixture was heated at reflux for 5hours and cooled to room temperature. An orange precipitate was filteredoff and washed with isopropanol and diisopropyl ether, affordingintermediate b [S. Yu. Ryabova, N. Z. Tugusheva, L. M. Alekseeva, V. G.Granik Pharmaceutical Chemistry Journal 1996, 30, 472-477] (20.71 g,yield=62%, purity(LC)>98%).

Intermediate b (0.070 mol, 20.71 g) was mixed with methanol (200 ml) andtriethylamine (3 equiv., 0.210 mol, 21.27 g) and the mixture was heatedat reflux for 4 hours, cooled to room temperature and evaporated underreduced pressure to a dry powder. The crude product c [S. Yu. Ryabova,N. Z. Tugusheva, L. M. Alekseeva, V. G. Granik Pharmaceutical ChemistryJournal 1996, 30, 472-477] (purity(LC)>95%) was used as such in the nextstep.

To ice-cooled N,N-dimethylformamide (hereinafter referred to as DMF) (50ml) was added dropwise phosphorus oxychloride (3 equiv., 0.210 mol,32.22 g) keeping the internal temperature <10° C. and the cooled mixturewas stirred for 1 hour. Then, a solution of c in DMF (100 ml) was addeddropwise, keeping the reaction temperature <10° C. during the addition.The ice-bath was removed and the reaction mixture was stirred at roomtemperature for 1.5 hours. The mixture was poured into ice-water (1liter) and then heated overnight at 60° C. and cooled to roomtemperature. The precipitate was isolated by filtration, washedsuccessively with water, isopropanol and diisopropyl ether to affordintermediate d [S. Yu. Ryabova, N. Z. Tugusheva, L. M. Alekseeva, V. G.Granik Pharmaceutical Chemistry Journal 1996, 30, 472-477] (15.93 g,yield=81%, purity (LC)>95%).

To a mixture of d (0.056 mol, 15.93 g) in isopropanol (150 ml) was addedtriethylamine (1.5 equiv., 0.085 mol, 8.59 g) and ethyl cyanoacetate(0.068 mol, 7.69 g). The mixture was heated at reflux for 2 hours,cooled to room temperature, filtered and the residue was successivelywashed with isopropanol and diisopropyl ether to afford intermediate e[S. Yu. Ryabova, L. M. Alekseeva, B. G. Granik Chemistry of HeterocyclicCompounds 2000, 36, 301-306] (16.42 g, yield=78%, purity(LC)>95%).

A stirred suspension of d (0.043 mol, 16.42 g) in ethyleneglycol (200ml) was heated at reflux for 2 hours and cooled to room temperature. Theprecipitate was isolated by filtration and washed successively withisopropanol and diisopropyl ether. Crude compound 1 was crystallisedfrom DMF/water as follows: the crude precipitate was dissolved in warmDMF (250 ml). To the warm solution, water (100 ml) was added and thesolution was cooled to room temperature, allowing compound 1 toprecipitate. The precipitate was isolated by filtration and washedsuccessively with isopropanol and diisopropyl ether to afford compound1² (10.52 g, yield=73%, purity(LC)>98%). ¹H NMR (δ, DMSO-D6): 6.11 (1H,d, J≈8 Hz), 6.86 (1H, t, J≈8 Hz), 7.38 (1H, t, J≈8 Hz), 7.54 (1H, d, J≈8Hz), 7.91 (2H, d, J=8.6 Hz), 8.55 (2H, d, J=8.6 Hz), 8.70 (1H, s), 12.00(1H, br s).

To a mixture of compound 1 (6.05 mmol, 2.0 g) in DMF (20 ml) was addedpotassium carbonate (2 equiv., 12.11 mmol, 1.674 g) and methyl iodide(1.5 equiv., 9.08 mmol, 1.289 g) and the mixture was heated at refluxfor 2 hours. The warm suspension was further diluted with DMF (40 ml).Water (40 ml) was added dropwise to the warm solution and the mixturewas cooled to room temperature, allowing compound 2 to crystallise. Theprecipitate was isolated by filtration and washed successively withisopropanol and diisopropyl ether, affording compound 2 (2.085 g,yield=91%, purity (LC)>98%). ¹H NMR (δ, DMSO-D6): 3.93 (3H, s), 6.12(1H, d, J≈8 Hz), 6.89 (1H, t, J≈8 Hz), 7.45 (1H, t, J≈8 Hz), 7.64 (1H,d, J≈8 Hz), 7.89 (2H, d, J=8.5 Hz), 8.54 (2H, d, J=8.5 Hz), 8.99 (1H, s)

A solution of tin(II) chloride dihydrate (10 equiv., 0.060 mol, 13.54 g)in concentrated hydrochloric acid (20 ml) was added dropwise to a cooled(0° C.) solution of 1 (0.006 mol, 2 g) in ethanol 50 ml). The mixturewas heated at 60° C. for 4 hours. The solution was cooled to roomtemperature and aqueous saturated sodium bicarbonate was added untilpH>7. Compound 54 was isolated by filtration and washed successivelywith isopropanol and diisopropyl ether (1.23 g, yield=68%(purity(LC)>98%).

N,N-dimethylformamide dimethyl acetal (10 equiv., 3.33 mmol, 396 mg) wasadded to a mixture of compound 54 (0.333 mmol, 100 mg) in DMF (1 ml).The reaction mixture was heated at reflux for 1 hour. After cooling, thereaction mixture was cooled to room temperature, the solution wasdiluted with diisopropyl ether and stirred for ½ hour. The precipitatewas isolated by filtration and washed with diisopropyl ether affordingcompound 40 (103 mg, yield=84%, purity (LC)=96%).

To a stirred solution of 7 (0.312 mmol, 107 mg) in ethanol (1 ml), asolution of tin(II) chloride dihydrate (3.5 equiv., 1.09 mmol, 245 mg)in concentrated hydrochloric acid (0.4 ml) was added and the reactionmixture was stirred at 60° C. for 2 hours. The reaction mixture wasdiluted with water and sodium bicarbonate was added until pH>7. Theprecipitate was isolated by filtration. The precipitate was washed withisopropanol and diisopropyl ether affording crude compound 89 that wasused as such in the next step.

A solution of 2,5-dimethoxytetrahydrofuran (160 mg, 1.21 mmol, 2.9equiv.) in acetic acid (2.5 ml) was added dropwise to a solution of theamine 89 (132 mg, 0.42 mmol) in acetic acid (5 mL) at 90° C. The mixturewas stirred at 90° C. for 5 minutes and cooled to room temperature. Theprecipitate was filtered and washed with water. 130 mg brown solid wasobtained. The crude product was further purified by preparative HPLC,affording compound 59 (63 mg, yield=41%, purity (LC)=94%) as brownsolid.

To a mixture of the amine 89 (104 mg, 0.33 mmol) in pyridine (3 ml) wasadded diformylhydrazine (87 mg, 0.99 mmol), followed by trimethylsilylchloride (539 mg, 4.96 mmol) and triethylamine (234 mg, 2.32 mmol)dropwise. The reaction was heated at 100° C. for 2.5 hours and cooled toroom temperature. The mixture was concentrated and co-evaporated withtoluene. The resulting residue was taken up into methanol and filtered.The filtrate was concentrated to give 110 mg of a yellow solid. Thecrude product was purified by preparative HPLC affording compound 61 asa bright-yellow solid (50 mg, yield=41%).

Method A: To a stirred solution of compound 1 (0.6 mmol, 0.200 g) in DMF(15 ml) was added potassium carbonate (3 equiv., 1.8 mmol, 0.248 g) and1-(2-chloroethyl)-pyrrolidine hydrochloride (1.5 equiv., 0.9 mmol, 0.152g) and the mixture was heated at reflux for 5 hours. The mixture wascooled to room temperature, water was added and the precipitate wasisolated by filtration and washed successively with isopropanol anddiisopropyl ether to afford compound 13 (0.192 g, yield=75%,purity(LC)>95%).

Method B: To a stirred mixture of compound 1 (6.1 mmol, 2.00 g) in DMF(20 ml) was added-under N₂-atmosphere at room temperature-sodium hydride(13 mmol, 0.538 g 60%). The reaction mixture was stirred at roomtemperature for 30 min and 1-(2-chloroethyl)pyrrolidine (6.6 mmol, 1.13g) was added portionwise. The mixture was stirred overnight at roomtemperature. The solvent was removed under reduced pressure, water wasadded the aqueous solution was extraction with ethylacetate (3×). Theorganic phase was dried (MgSO₄), filtered and the solvent was removedunder reduced pressure. The crude product was purified on silica(dichloromethane/methanol 90/10) to yield compound 13 (1.023 g,yield=40% (LC), purity >98%).

To a mixture of compound 1 (3 mmol, 1.00 g) in DMF (25 ml), was addedsodium hydride (1.2 equiv., 3.6 mmol, 172 mg of 50% NaH in mineral oil)and the mixture was heated for 1 hour to 50° C. The mixture was cooledto room temperature and 1-bromo-3-chloropropane (1.5 equiv. 4.5 mmol,0.702 g) was added. The reaction mixture was stirred overnight at roomtemperature. The reaction mixture containing intermediate f was used assuch in the next step.

Pyrrolidine (1.5 equiv., 0.909 mmol, 0.065 g) was added to 5 ml of thereaction mixture of the former step containing intermediate f (0.606mmol) and the mixture was heated for 5 hours at 70° C. The reactionmixture was cooled to room temperature, precipitated with water andsuccessively washed with isopropanol and diisopropyl ether. Purificationby preparative HPLC gave compound 24 (0.040 g, yield=15%, purity(LC)>95%).

To a stirred mixture of compound 1 (2 mmol, 0.660 g) in DMF (7.5 ml) wasadded potassium carbonate (6 mmol, 0.828 g) andtert-butyl-2-bromoacetate (2 equiv., 4 mmol, 0.776 g) and the mixturewas heated to reflux for 1 hour. Compound 125 was not isolated and usedas such in the next step.

To the crude reaction mixture of compound 18 was added 12 N hydrochloricacid until pH=0-1. The mixture was heated to reflux for 1 hour, cooledto room temperature and precipitated with water. The precipitate wasisolated by filtration and washed successively with water, isopropanoland diisopropyl ether to afford compound 19 (0.495 g, yield=64%, purity>98%).

To a mixture of compound 19 (0.13 mmol, 0.0050 g) in DMF (4 ml) wasadded 1,1′-carbonyldiimidazole and the mixture was stirred at roomtemperature for 2 hours. 1-Methylpiperazine was added and the mixturewas stirred overnight at room temperature. Compound 20 precipitated onthe addition of water and the product was isolated by filtration. Theprecipitate was successively washed with isopropanol and diisopropylether to give 20 (0.039 g, yield=63%, purity (LC)>95%).

To a mixture of compound 2 (2.90 mmol, 1.00 g) in ethanol (20 ml) wasadded hydroxylamine hydrochloride (5 equiv., 14.52 mmol, 1.01 g) andpotassium carbonate (6 equiv., 17.43 mmol, 2.408 g). The mixture washeated at reflux for 24 hours, cooled to room temperature and theprecipitate was isolated by filtration and successively washed withwater, isopropanol and diisopropyl ether to afford compound 70 (0.933 g,yield=81%, purity (LC)=94%).

To a mixture of compound 70 (0.265 mmol, 0.100 g) in pyridine (15 ml)was added trifluoroacetic anhydride (1.2 equiv., 0.318 mmol, 0.038 g)and triethylamine (1.5 equiv., 0.400 mmol, 0.040 g) and the mixture washeated at reflux for 12 hours. The solvent was removed under vacuum andthe residue was purified by chromatography over silica gel withdichloromethane/methanol (95/5) to afford compound 72 (0.044 g,yield=33%, purity (LC)=91%).

To a stirred mixture of compound 70 (0.265 mmol, 0.100 g) inacetonitrile (15 ml) was added 1,1′-carbonyldiimidazole (0.318 mmol,0.052 g) and the mixture was heated at reflux overnight. The mixture wascooled to room temperature, water was added and extracted withdichloromethane (3×30 ml). After evaporation of the aqueous layer,compound 63 was obtained (0.058 g, yield=45%, purity=83%).

To a stirred mixture of compound 70 (0.265 mmol, 0.100 g) inacetonitrile (15 ml) was added 1,1′-thiocarbonyldiimidazole (0.318 mmol,0.057 g) and 1,8-diazo-bicyclo[5.4.0]undec-7-ene (0.318 mmol, 0.048 g)and the mixture was heated at 80° C. for 1 hour. The solvent was removedunder reduced pressure, water was added and the mixture was acidifiedwith 1N hydrochloric acid to pH=1. The precipitate was filtered andwashed successively with water, isopropanol and diisopropyl ether. Theprecipitate was recrystallized from DMF/water and the crystals whereisolated by filtration and washed successively with water, isopropanoland diisopropyl ether to afford compound 73 (0.063 g, yield=54%, purity(LC)=96%).

To a mixture of intermediate d (7.43 mmol, 2.091 g) in methanol (50 ml)was added dimethylmalonate (1.2 equiv., 8.92 mmol, 1.179 g) andpiperidine (catalytic) and the mixture was heated at reflux for 5 hours.The precipitate was filtered off and successively washed withisopropanol and diisopropyl ether to yield compound 74 (1.53 g,yield=54%, purity (LC)=95%)

To a mixture of compound 74 (3.48 mmol, 1.265 g) in DMF (35 ml) wasadded methyliodide (1.5 equiv., 5.22 mmol, 0.741 g) and potassiumcarbonate (2 equiv., 6.963 mmol, 0.962 g). The mixture was heated to100° C. for 2 hours, cooled to room temperature and, upon the additionof water, a precipitate was formed. The precipitate was filtered of andsuccessively washed with isopropanol and diisopropyl ether to yieldcompound 75 (1.213 g, yield=92%, purity (LC)=98%).

To a mixture of compound 75 (0.53 mmol, 0.200 g) in DMF (5 ml) was addedsodium methoxide (2 equiv., 1.06 mmol, 0.057 g) dissolved in methanol (2ml) and formamide (10 equiv., 5.30 mmol, 0.239 g) and the mixture washeated to 100° C. for 1 hour. The reaction was cooled to roomtemperature and, upon the addition of water, a precipitate was formed.The precipitate was filtered and successively washed with isopropanoland diisopropyl ether to yield compound 76 (0.150 g, yield=78%,purity(LC)=97%)

A solution of potassium hydroxide (1.10 mmol, 0.062 g) in water (3 ml)was added to a stirred solution of compound 74 in methanol (7 ml) andthe mixture was heated at reflux for 2 hours. The mixture was cooled toroom temperature and acidified with 2N hydrochloric acid until theproduct precipitated. The precipitate was isolated by filtration anddried overnight in a vacuum oven at 50° C. to yield compound 77 (0.110g, yield=40%, purity (LC)>98%).

Compound 1 (0.303 mmol, 100 mg) was dissolved in DMF (2 ml). Sodiumazide (15 equiv., 4.545 mmol, 294 mg) and ammonium chloride (15 equiv.,4.545 mmol, 240 mg) were added in equal portions over 6 days while thereaction mixture was stirred at 125° C. The reaction mixture was cooledto room temperature, poured into water (30 ml) and stirred at roomtemperature for ½ hour. The precipitate was isolated by filtration. Theprecipitate was washed with water. Recrystallisation fromacetonitrile/acetone afforded compound 69 (23 mg, yield=20%, purity(LC)>95%).

To a mixture of intermediate d (1.00 mmol, 0.281 g) in THF (10 ml), wasadded potassium tert-butoxide (1.10 equiv., 1.10 mmol, 0.123 g) andethyl 3-pyridylacetate (1.00 equiv., 1.00 mmol, 0.165 g). The mixturewas stirred and heated at 90° C. overnight. The reaction mixture wasconcentrated. The residue was dissolved in ethyl acetate and washed withwater. The organic phase was dried with magnesium sulphate, filtered andevaporated to dryness. The residue was purified with preparative HPLC,affording compound 64 (0.008 g, yield=2%, purity (LC)>50%).

To a mixture of N-acetyl-3-hydroxyindole (0.057 mol, 10.00 g) in toluene(100 ml), 4-bromoaniline (1.1 equiv., 0.063 mol, 10.80 g) and acatalytic amount of p-toluene-sulfonic acid were added. The reactionmixture was heated at reflux for 4 hours with azeotropic removal ofwater. Upon cooling to room temperature, intermediate g crystallised.The precipitate was isolated by filtration and washed with toluene,affording intermediate g (9.60 g, yield=51%, purity (LC)>95%).

A mixture of g (0.056 mol, 18.53 g) in chloroacetyl chloride (85 ml) washeated at reflux for 15 minutes. The reaction mixture was concentratedunder reduced pressure. Isopropanol (50 ml) was added to the residue andthe reaction mixture was heated to reflux for 10 minutes. The reactionmixture was cooled, the precipitate was filtered and washed withisopropanol, affording intermediate h (17.00 g, yield=74%, purity(LC)=95%).

To a mixture of intermediate h (0.0419 mol, 17.00 g) in methanol (170ml), triethylamine (1.2 equiv., 0.0503 mol, 5.09 g) was added. Thereaction mixture was heated at reflux for 1 hour. The cooled reactionmixture was filtered. The precipitate was washed with diethyl ether,affording intermediate i (13.41 g, yield=88%, purity (LC)=95%).

In a first reaction vessel, potassium cyanide (2.50 equiv., 0.0965 mol,6.28 g) was added to a solution of intermediate i (0.0386 mol, 14.03 g)in DMF (140 ml). The reaction was heated at reflux for 3 hours andcooled to room temperature. In a second reaction vessel, dry DMF (45 ml)was cooled to 0° C. Phosphorus oxychloride (2.5 equiv., 0.0965 mol, 14.8g) was added dropwise keeping the internal temperature <10° C. and thereaction mixture was stirred at 0° C. for an additional ½ hour. Thecontents of first reaction vessel were then added dropwise to thestirred POCl₃-DMF complex in the second reaction vessel while thetemperature was kept <10° C. The reaction mixture was stirred overnightat room temperature, poured into water (860 ml) and stirred at 70° C.for 6 hours. The cooled reaction mixture was filtered. The precipitatewas washed with isopropanol and diisopropyl ether, affording compound 38(12.18 g, yield=87%, purity (LC)>95%).

N,N-Dimethylformamide dimethyl acetal (10 equiv., 0.233 mol, 27.72 g)was added to a solution of compound 38 (0.0233 mol, 8.49 g) in DMF (85ml). The reaction mixture was heated at reflux for 1 hour. The reactionmixture was cooled to room temperature, poured into water (500 ml) andstirred for ½ hour. The precipitate was isolated by filtration, washedwith water and diisopropyl ether, affording compound 39 (4.54 g,yield=51%, purity (LC)=95%). ¹H NMR (δ, DMSO-D6): 3.92 (3H, s), 6.10(1H, d, J≈8 Hz), 6.91 (1H, t, J≈8 Hz), 7.44 (1H, t, J≈8 Hz), 7.52 (2H,d, J=8.6 Hz), 7.63 (1H, d, J≈8 Hz), 7.91 (2H, d, 8.6 Hz), 8.95 (1H, s).

Tris(dibenzylideneacetone)dipalladium(0) (0.1 equiv., 0.026 mmol, 24 mg)was added to a solution of tri(t-butyl)phosphine in toluene (0.24equiv., 0.0635 mmol, 0.4 M, 159 μl) in a sealed tube. Dry THF (3 ml) wasadded and the reaction mixture was stirred under nitrogen at roomtemperature for 10 minutes. In a second sealed tube, compound 39 (0.264mmol, 100 mg), 3-furylboronic acid (2 equiv., 0.53 mmol, 59 mg) andpotassium fluoride (3.3 equiv., 0.87 mmol, 51 mg) were mixed and to thisstirred suspension, the solution from the first sealed tube was addedwith a syringe. The reaction mixture was stirred under nitrogen at roomtemperature for 2 days. The reaction mixture was filtered over decaliteand the decalite was washed with dichloromethane (100 ml). The combinedfiltrates were concentrated in vacuo, affording a dark brown oil. Thisresidue was dissolved in DMF (2 ml), poured into water (20 ml) andstirred at room temperature for ½ hour. The precipitate was isolated byfiltration, washed with water, isopropanol and diisopropyl ether andfurther purified by preparative HPLC, affording compound 58 (25 mg,yield=26%, purity (LC)>95%).

To a mixture of N-acetyl-3-hydroxyindole a (85.624 mmol, 15 g) in aceticacid (150 ml) was added 4-aminobenzonitrile (1.5 equiv., 0.128 mol,15.17 g) and the mixture was heated at reflux for 4 hours. The reactionmixture was cooled on ice for 1 hour, allowing the reaction product tocrystallize. The precipitate was filtered off and washed successivelywith isopropanol and diisopropyl ether, affording intermediate j as awhite powder (9.24 g, yield=58%, purity(LC)>98%).

To a mixture of intermediate j (0.053 mol, 14.7 g) in acetic anhydride(150 ml) was added a catalytic amount of dimethylaminopyridine, and themixture was heated at reflux overnight. The solvent was removed underreduced pressure to give a black tar, containing intermediate k. Thecrude reaction mixture was used as such in the next step.

The crude mixture of intermediate k was dissolved DMF (200 ml) andcooled on an ice bath. To this stirred reaction mixture, a premixedsolution (using cooling) of phosphorus oxychloride (5 equiv., 0.31 mol,30 ml) and DMF (50 ml) were added dropwise and stirring at 0° C. wascontinued for a few hours. Then, the contents of the reaction werepoured into ice-water (1.51) and heated at reflux overnight. The mixturewas allowed to cool to room temperature, filtered and the precipitatewas washed successively with water, isopropanol, diisopropyl etheraffording compound 93 as black crystals (12.4 g, yield=81% (two steps),purity (LC)>98%)

To a mixture of compound 93 (0.043 mol, 12.4 g) in DMF (120 ml) wasadded N,N-dimethylformamide dimethyl acetal (5 equiv., 0.217 mol, 29 ml)and the mixture was heated at reflux. After 3 h another portion ofN,N-dimethylformamide dimethyl acetal (5 equiv., 0.217 mol, 29 ml) wasadded and the reaction mixture was heated at reflux overnight. Thereaction mixture was poured into a mixture of water (800 ml) and aceticacid (10 ml) and stirred for 1 hour to give a black precipitate. Theprecipitate was filtered off and washed successively with water,isopropanol and diisopropyl ether affording compound 96 as a blackpowder (8.20 g, yield=63%, purity (LC)>98%). ¹H NMR (δ, DMSO-D6): 3.90(3H, s), 6.06 (1H, d, J≈8 Hz), 6.61 (1H, d, J=9.60 Hz), 6.85 (1H, t, J≈8Hz Hz), 7.31 (1H, t, J≈8 Hz), 7.58 (1H, d, J≈8 Hz), 7.72 (2H, d, J=8.3Hz), 8.15->8.19 (3H, m)

To a stirred solution of 96 (40.758 mmol, 12.2 g) in ethanol (130 ml)was added hydroxylamine hydrochloride (5 equiv., 0.143 mol, 9.91 g) andpotassium carbonate (6 equiv., 0.171 mol, 23.6 g) and the mixture washeated at 70° C. overnight. The solvent was removed under reducedpressure. The residue was taken up in dichloromethane (250 ml) and water(11) and vigorously stirred for 1 hour. The mixture was filtered and theprecipitate washed with water, isopropanol and diisopropyl etheraffording compound 97 as a black powder (5.68 g, yield=60%, purity(LC)=90%)

To a stirred solution of compound 97 (0.0003 mol, 100 mg) in pyridine (2ml), was added acetyl chloride (1.2 equiv., 0.00036 mol, 28 mg) and thereaction mixture was heated at reflux overnight. The solvent was removedunder reduce pressure, the residue was taken up in dichloromethane (25ml) and washed with brine. The organic layer was dried with magnesiumsulfate, filtered and the solvent was removed under reduced pressure.The product was purified by flash chromatography (eluent:dichloromethane/methanol: 9/1) affording compound 103 as orangecrystals.

To a mixture of compound 97 (0.3 mmol, 100 mg) in acetonitrile (5 ml)was added 1,1′-carbonyldiimidazole (1.2 equiv., 0.36 mmol, 0.060 g) andstirred under heating (80° C.) for 6 hours. The solvent was removedunder reduced pressure, the residue was taken up in dichloromethane (25ml) and brine (25 ml) and vigorously stirred for 30 min. Filtration ofthe solvent mixture afforded compound 83 (0.067 g, yield=62%, purity(LC)>98%).

A flask containing compound 83 (0.1 g, 0.279 mmol) was equipped with aCaCl₂ tube. Phosphorus oxychloride (3 ml) was added dropwise and themixture was heated at reflux overnight. The reaction mixture was pouredinto ice-water (150 ml) and stirred for 1 hour. The mixture was filteredand washed with water, isopropanol, and diisopropyl ether affordingcompound 126 (0.080 g, yield=71%, purity (LC)=93%).

To a stirred solution of compound 126 (0.090 g, 0.239 mmol) inacetonitrile (4 ml) was added methylamine 40% in water (10 equiv, 2.390mmol, 269 mg) and the reaction mixture was stirred at room temperaturefor 2 hours. The solvent was removed under reduced pressure affordingcompound 120 (0.091 g, yield=99%, purity >95%).

To a mixture of compound 83 (0.279 mmol, 0.100 g) and potassiumcarbonate (2 equiv., 0.519 mmol, 0.071 g) in DMF (5 ml) was addeddropwise methyl iodide (2 equiv., 0.519 mmol, 0.074 g) in DMF (5 ml).The reaction mixture was stirred a room temperature for 5 h. The solventwas removed under reduced pressure and the residue was mixed with water(100 ml) and vigorously stirred for 1 hour. The precipitate was filteredoff and washed with water, isopropanol and diisopropyl ether affordingcompound 117 (0.072 g, yield=74%, purity (LC)=90%).

Compound 6 (0.100 g, 0.3 mmol) was heated at reflux for 1 hour in formicacid (2.5 ml). Then, the solvent was evaporated under reduced pressure.The product was purified by flash chromatography (eluent:dichloromethane/methanol: 9/1) affording compound 82 (0.022 g,yield=16%, purity (LC)=77%).

To a mixture of compound 97 (0.200 g, 0.6 mmol) and triethylamine (1.5equiv., 0.9 mmol, 0.091 g) in THF (3 ml) was added dropwise a solutionof ethyl oxalyl chloride (1.2 equiv., 0.72 mmol, 0.1 g) in THF (1 ml).The mixture was stirred at room temperature for 1.5 hour. Then, underargon atmosphere, tetrabutylammonium fluoride (0.3 equiv, 0.18 mmol,0.048 g) was added and the mixture was stirred overnight. The reactionmixture was iluted with ethyl acetate (40 ml) and washed with water andbrine. The organic layer was dried with magnesium sulfate, filtered andthe solvent was removed under reduced pressure. The crude product wasrecrystallized from ethyl acetate/hexane, affording compound 119 as ayellow powder (0.006 g, yield=2%, purity (LC)>95%).

To a mixture of compound 97 (0.1 g, 0.3 mmol) in acetonitrile (3 ml) wasadded 1,1′-thiocarbonyldiimidazole (1.2 equiv., 0.36 mmol, 0.064 g) and1,8-diazabicyclo-[5.4.0]undec-7-ene (1.2 equiv., 0.36 mmol, 0.055 g) andthe mixture was heated at reflux for 1 hour. The solvent was removedunder reduced pressure and the residue was washed with water,isopropanol, diisopropyl ether affording compound 118 (0.081 g,yield=72%, purity (LC)>95%).

Compound 96 (0.175 mmol, 50 mg) was dissolved in DMF (2 ml). Sodiumazide (10.4 equiv., 1.848 mmol, 120 mg) and ammonium chloride (11.6equiv., 2.036 mmol, 108 mg) were added in 10 equal portions over 50 hourwhile the reaction mixture was heated at 125° C. The reaction mixturewas cooled to room temperature. Then it was poured into ice-water (30ml). The reaction mixture was acidified with 1 N hydrochloric acid andstirred at room temperature for 1 hour. A precipitate was isolated byfiltration. The precipitate was washed with water, isopropanol anddiisopropyl ether. The precipitate was purified by preparative HPLC,affording compound 95 (1 mg, yield=2%, purity (LC)>95%)

To a mixture of compound 96 (0.0083 mol, 2.5 g) in dichloromethane (50ml) was added N-bromosuccinimide (1 equiv., 0.0083 mol, 1.48 g) and themixture was stirred at room temperature for 4 hours. The solvent wasremoved under reduced pressure. The reaction mixture was dissolved inDMF (30 ml) and precipitated by the addition of water (150 ml). Theprecipitate was filtrated and washing with water, isopropanol,diisopropyl ether, affording compound 127 (2.59 g, yield=74%, purity(LC)=91%)

To a mixture of compound 127 (0.50 mmol, 0.190 g) in toluene (3 ml),ethanol (1 ml) and water (5 drops), was added potassium carbonate (1.20equiv., 0.60 mmol, 0.083 g), tetrakis(triphenylphosphine)palladium(0)(0.10 equiv., 0.05 mmol, 0.058 g) and 2-Furylboronic acid (1.20 equiv.,0.60 mmol, 0.067 g). The mixture was stirred and heated at 100° C.overnight. The reaction mixture was concentrated in vacuo and theresidue was dissolved in ethyl acetate and washed with water. Theorganic phase was dried with MgSO₄, filtered, and evaporated underreduced pressure. The residue was purified by chromatography usingsilica gel, affording compound 88 (yield=54%, purity=90%).

To a mixture of compound 96 (0.3344 mmol, 0.100 g) in ethanol (9 ml) andwater (1 ml) was added potassium hydroxide (1 equiv., 0.3344 mmol, 0.019g). The reaction mixture was heated at reflux overnight and the solventwas removed under reduced pressure. The residue was dissolved indichloromethane, washed with water, dried with magnesium sulfate andfiltered. The solvent was removed under reduced pressure affordingcompound 98 (0.055 g, yield=52%, purity (LC)>95%).

To a mixture of compound 96 (1.670 mmol, 0.5 g) in ethanol (5 ml) wasadded sodium hydroxide 50% in water (0.5 ml), and the mixture was heatedat reflux overnight. The reaction mixture was diluted with water and 1Nhydrochloric acid was added until pH=2 causing 99 to precipitate. Theprecipitate was filtered off, washed with water, and dried in a vacuumoven at 50° C. affording compound 99 as a brown powder (0.46 g,yield=87%, purity (LC)>95%).

To a mixture of compound 99 (0.628 mmol, 0.200 g) in dichloromethane (7ml) was added thionylchloride (3 ml) in 3 portions over 24 h while themixture was heated at reflux. The solvent was removed under reducedpressure and the residue was dissolved in ethanol (5 ml). To thisstirred solution was added sodium hydroxide 50% in water (1 ml), and themixture was stirred at room temperature for 1 hour. The reaction mixturewas diluted with water and 1N hydrochloric acid was added until pH=2causing compound 87 to precipitate. The precipitate was filtered off,washed with water, and dried in a vacuum oven at 50° C. affording 87 asa brown powder (0.033 g, yield=12%, purity (LC)=87%).

To a vigorously stirred solution of DMF (25 ml), saturated withhydrochloric acid, was added 96 (1 g, 3.34 mmol) and thioacetamide (2equiv., 0.502 g, 6.7 mmol). The mixture was stirred at 60° C. for 12hours. The mixture was added slowly to an aqueous saturated solution ofKHCO₃ (50 ml). The aqueous solution was extracted with ethyl acetate(3×20 ml) and the combined fractions were dried (MgSO₄) and evaporatedunder reduced pressure to give compound 128 (500 mg, 45%) as a solid.

To a stirred solution of thioamide 128 (170 mg, 0.5 mmol) in ethanol (20ml), bromopyruvic acid (1.2 equiv., 103 mg, 0.6 mmol) was added. Themixture was heated to reflux for 3 hours. The solvent was evaporatedunder reduced pressure and purified by preparative HPLC to give acompound 81 (20 mg, yield=11%) as a solid.

To a stirred solution of compound 91 (25 mmol, 83 mg) in DMF (1 ml) wasadded 2N NaOH (2 ml) and the mixture was heated at 100° C. for 1 hour.The mixture was cooled to room temperature, diluted with water (10 ml)and acidified with concentrated hydrochloric acid to pH=1 causing awhite powder to precipitate. The powder was isolated by filtration andsuccessively washed with water, isopropanol and diisopropyl ether toafford 94 (67 mg, yield=88%, purity (LC)>97%)

To a mixture of compound 94 (0.329 mmol, 100 mg) in dry DMF (2 ml),1,1′-carbonyldiimidazole (1.2 equiv., 0.395 mmol, 64 mg) was added. Thereaction mixture was stirred at room temperature for 1 hour. Then asolution of 40% dimethylamine in water (1 ml) was added and the reactionmixture was stirred at room temperature overnight. The reaction mixturewas concentrated and the residue was purified by preparative HPLC,affording compound 79 (11 mg, yield=10%, purity (LC)=88%)

To a mixture of 3-acetylindole 1 (0.157 mol, 25.0 g) in DMF (200 ml) wasadded potassium carbonate (1.05 equiv., 0.165 mol, 22.8 g) and methyliodide (1.1 equiv., 0.173 mol, 24.5 g). The mixture was stirred at roomtemperature overnight. To the mixture was added potassium carbonate (2.1equiv., 0.330 mol, 45.6 g) and methyl iodide (2.2 equiv., 0.346 mol,49.0 g). The mixture was stirred at room temperature for 3 hours. Themixture was concentrated under reduced pressure to ⅕^(th) of theoriginal volume. The residue was dissolved in dichloromethane and washedwith water. The organic phase was dried with MgSO₄, concentrated invacuo, affording intermediate m (purity (LC)=90%). The crude product wasused without further purification in the next step.

To a mixture of intermediate m (0.312 mol, 54.0 g) in ethanol (150 mland water (100 ml) was added acetic acid, sodium salt (2.4 equiv., 0.748mol, 61.0 g) and hydroxylamine hydrochloride (3 equiv., 0.935 mol, 65.0g). The mixture was stirred and heated at reflux for 2.5 hours. Themixture was cooled to room temperature. The reaction mixture was pouredinto water (750 ml). The precipitate was isolated by filtration andwashed with water. The crude precipitate was dissolved in THF (200 ml)and toluene (50 ml) and the mixture was evaporated to dryness (2×),affording intermediate n (purity (LC)=80%). The crude product was usedas such in the next reaction.

Intermediate n (0.312 mol, 58.7 g) was dissolved in acetic acid (300ml). The mixture was stirred and heated at reflux for 2 hours. Themixture was concentrated in vacuo. Toluene (100 ml) added and evaporatedto dryness (2×). Crystallization from ethanol (400 ml) gave crudeintermediate p (31.0 g, purity (LC)=90%). Recrystallization in ethanol(300 ml) afforded p [C. Papamicäel, G. Quéguiner, J. Bourguignon, G.Dupas Tetrahedron 2001, 57, 5385-5391] as brown crystals (29.4 g,yield=50%, purity (LC)>98%).

To cooled (0° C.) dry DMF (40 ml) was added dropwise phosphorusoxychloride (2.5 equiv., 0.199 mol, 30.6 g) and the reaction mixture wasstirred for 0.5 h at 0° C. Then, a solution of p (0.080 mol, 15.0 g) inDMF (160 ml) was added. The cooling was removed and the reaction mixturewas allowed to warm to room temperature overnight. The reaction mixturewas poured into ice-water (21) and stirred for 0.5 hours. A brownprecipitate was isolated by filtration and washed with water. Theprecipitate was dried for 24 hours in open air, affording intermediate qas a brown powder (6.10 g, yield=35%, purity (LC)=95%).

A mixture of intermediate q (0.005 mol, 1.13 g), Pd/C-catalyst (10%,0.50 g) and triethylamine (6.8 equiv., 0.036 mol, 3.60 g) in THF (200ml) was hydrogenated at atmospheric pressure for 2 hours. The catalystwas removed by filtration. The filtrate was evaporated to give r as abrown powder (0.88 g, yield=92%, purity (LC)>95%).

To a mixture of intermediate r (0.005 mol, 0.880 g) and ethanol (5 ml)was added 3-chloroperoxybenzoic acid (70-75%, 1.2 equiv., 0.006 mol,1.43 g). The reaction mixture was heated at reflux for 2 hours. Pyridine(0.5 equiv., 0.002 mol, 0.190 g) was added and the mixture was heated atreflux for 0.5 h. The reaction mixture was cooled to room temperatureand evaporated in vacuo to dryness. The residue was mixed with aceticanhydride (10 ml) and heated at reflux for 4 h and evaporated to dry.The residue was dissolved in 2N potassium hydroxide (50 ml) and stirredfor 1 h. The pH of the reaction mixture was adjusted to 1 by theaddition of concentrated hydrochloric acid. A brown precipitate wasisolated by filtration. The precipitate was washed with a saturatedsodium bicarbonate solution (2×10 ml), water, isopropanol anddiisopropyl ether, affording intermediate s as a brown powder (0.680 g,yield=71%, purity (LC)>95%).

A mixture of s (0.001 mol, 0.2 g), copper(II) acetate (2 equiv., 0.002mol, 0.366 g), 4-acetylphenylboronic acid (2 equiv., 0.002 mol, 0.328 g)and powdered molecular sieves (4 Å) in DMF/pyridine (9/1) (3 ml) washeated in a stoppered flask at 80° C. overnight. The molecular sieveswere removed by filtration and washed with acetonitrile. The combinedfiltrates was evaporated under reduced pressure and the crude mixturewas purified with by preparative HPLC affording compound 122 (0.066 g,yield=21%, purity (LC)>95%).

To a mixture of compound 122 (0.316 mmol, 0.100 g) in acetonitrile (10ml) was added N,N-dimethylformamide dimethyl acetal (5 equiv., 1.581mmol, 0.1883 g) and the mixture was heated at reflux overnight. Thesolvent was removed under reduced pressure and the crude residue t wasused as such the next step.

To a crude mixture of intermediate t in acetic acid (3 ml) was addedhydroxylamine hydrochloride (4 equiv., 1.077 mmol, 0.0748 g) and aceticacid sodium salt (3 equiv., 0.8077 mmol, 0.0662 g). The mixture washeated (70° C.) overnight and the solvent was removed under reducedpressure. The product was purified using preparative HPLC affordingcompound 123 (0.021 g, yield=23%, purity (LC)=91%).

To a cooled (−78° C.) stirred suspension of sodium hydride (50% inmineral oil, 2.2 equiv., 44 mmol, 2.11 g) in tetrahydrofuran (30 ml),under a nitrogen atmosphere, was added dropwise, a solution ofintermediate u (20 mmol, 3.5 g) in tetrahydrofuran (50 ml) and thereaction was kept at −78° C. for 30 minutes. A solution ofethoxy-methylene ethyl cyanoacetate (1.1 equiv., 2.2 mmol, 3.72 g) intetrahydrofuran (30 ml) was added dropwise at −78° C. over a period of15 minutes. The reaction was kept at −78° C. for 1 hour. The cooling wasremoved and the mixture was allowed to warm to room temperatureovernight. The reaction mixture was poured into ice-water (400 ml) andacidified with concentrated hydrochloric acid to pH=1. A greenprecipitate was filtered and dried overnight in open air to affordintermediate v [J. Y. Mérour, S. Piroëlle J. Heterocyclic Chem. 1991,28, 1869-1873] (4.7 g, yield=92%, purity (LC)>95%).

Intermediate v (0.195 mmol, 50 mg) and 4-methoxyaniline (1.5 equiv.,0.293 mmol, 36 mg) were heated at reflux for 1 hour in acetic acid (2ml) and cooled to room temperature. A yellow precipitate was isolated byfiltration and washed with isopropanol and diisopropyl ether to affordcompound 90 (28 mg, yield=33%, purity (LC)=97%)

The following tables list examples of compounds of the present inventionwhich compounds have been prepared analogous to one of the foregoingsynthesis schemes.

TABLE 2

Comp. Synthesis No. scheme R² Salt form 1 A1 H 2 A1 CH₃ 3 A9

4 A7

5 A7

6 A7 benzyl 7 A7

8 A7 1-butyl 9 A7 ethyl 10 A7 cyclopentyl 11 A7

12 A7

13 A7

14 A7

chlorohydrate 15 A7

oxalate 16 A7

methanesulfonate 17 A7

18 A7

19 A9

20 A9

21 A8

22 A8

23 A8

24 A8

25 A8

26 A8

27 A7

28 A8

29 A8

30 A9

31 A7

32 A8

33 A7

34 A7

35 A7

36 A7

125 A9

TABLE 3

Comp. Synthesis No. scheme R² R_(3a) R_(3b) 37 B1 H F H 38 B1 H Br H 39B1 CH₃ Br H 40 A2 CH₃

H 41 A1 H F NO₂ 42 A1 H H NO₂ 43 A1 CH₃ H NO₂ 44 B1 CH₃ F H 45 A1 H CN H46 A1 CH₃ CN H 47 A7

CN H 48 B2 CH₃ 2-furanyl H 49 A7

CN H 50 A7

CN H 51 A7

CN H 52 B2 CH₃

H 53 B2 CH₃

H 54 A2 H NH₂ H 55 B2 CH₃

H 56 B1 CH₃ —O—CH₃ H 57 B2 CH₃

H 58 B2 CH₃

H 59 A5 CH₃

H 60 E1 CH₃ OH H 61 A6 CH₃

H

TABLE 4

Comp. Synthesis No. scheme R₁ R₂ 62 A10

CH₃ 63 A11

CH₃ 64 A15

H 65 A13

H 66 C1 H H 67 C1 H CH₃ 68 C9 Br CH₃ 69 A14

H 70 A10

CH₃ 71 A10

CH₃ 72 A10

CH₃ 73 A12

CH₃ 74 A13

H 75 A13

CH₃ 76 A13

CH₃ 77 A13

H 78 C9

CH₃

TABLE 5

Comp. Synthesis No. scheme R¹ R² R³ 79 D1 H H

80 C2 H CH₃

81 C12 H CH₃

82 C5 H CH₃

83 C3 H CH₃

84 C4 H CH₃

85 C2 H CH₃

86 C9 Br CH₃

87 C11 Cl CH₃ —COOH 88 C9 2-furanyl CH₃ —CN 89 A4 CN CH₃ —NH₂ 90 F1

H —OCH₃ 91 C1 H H

92 C1 H CH₃

93 C1 H H —CN 94 D1 H H —COOH 95 C8 H H

96 C1 H CH₃ —CN 97 C2 H CH₃

98 C10 H CH₃

99 C11 H CH₃ —COOH 100 C2 H CH₃

101 C2 H CH₃

102 C2 H CH₃

103 C2 H CH₃

104 C12 H CH₃

105 C12 H CH₃

106 C2 H CH₃

107 C2 H CH₃

108 C2 H CH₃

109 C2 H CH₃

110 C2 H CH₃

111 C2 H CH₃

112 C2 H CH₃

113 A10 + C2

H

114 C2 H CH₃

115 C2 H CH₃

116 A10 + C2

CH₃

117 C4 H CH₃

118 C7 H CH₃

119 C6 H CH₃

120 C3 H CH₃

121 E1 H CH₃ —I 122 E1 H CH₃

123 E2 H CH₃

124 C9

CH₃ —CN 126 C3 H CH

127 C9 Br CH₃ CN 128 C12 H CH₃

Time of Addition Experiment

A time of addition experiment was performed to determine the mechanismof action of the compounds of the present invention. In the time ofaddition experiment, compounds are added to cells that were infectedwith HIV, at time zero (Zero hours). The compounds are subsequentlyadded at different points in time. The time point until which a compoundcan be added to prevent virus replication, provides an indication of themechanism of action of the compound.

In the present experiment, MT4 cells were infected with HIV-1 strain LAIat time zero. In different experiments, compounds were subsequentlyadded at the points in time indicated in the X-axis of FIG. 1 (inhours). The compounds were added at the following end concentrationsduring incubation: DS5000, 1 μM; efavirenz (EFV), 1 μM; saquinavir(SQV), 1 μM; Reference 1, 10 μM (Reference 1 is an integrase inhibitorselected from WO 99/62520 and is present in CAS database: 251963-93-6);Compound 2, 50 μM; Control: normalized virus production. The virusproduction was determined using p24 monitoring using a kit according tothe manufacturers instructions (p24 ELISA kit, catalog referenceNEK-050, Perkin Elmer).

Compound 2 delayed virus production using a mechanism related to reversetranscriptase.

In Vitro Inhibition of HIV Reverse Transcriptase

The assay was run using kit TRK 1022 (Amersham Life Sciences) accordingto the manufacturer's instructions with slight modifications. Compoundswere diluted in steps of ¼ in 100% DMSO and subsequently transferred toMedium A ( 1/50 dilution; medium A: RPMI 1640+10% FetalCloneII+Gentamycin 20 mg/L). 25 μl of compound (in 2% DMSO in Medium A) or 25μl of 2% DMSO in medium A was added to wells. To each well was added25.5 μl master mix (master mix: 5 μl primer/template beads, 10 μl assaybuffer, 0.5 μl tracer (3H-TTP), 5 μl HIV RT enzyme solution at a finalenzyme activity of 15 mU per 50 μl reaction, 5 μl medium A). The plateswere sealed, marked as radioactive and incubated during 4 hours at 37°C. Subsequently, 100 μl stop solution was added to each well (exceptR1). The radioactivity was counted in a TopCount.

Compound 2 inhibits HIV reverse transcriptase in vitro and consequentlydoes not need conversion to an active metabolite in order to inhibitreverse transcriptase.

Metabolization of the Compounds of the Present Invention

The present experiment provides insight into the hepatic first passmetabolization of compounds.

Aliquots of human liver microsomal fractions (prepared by centrifugationat 12000 g⁻) were transferred into 10 ml glass tubes that are immersedin ice. Subsequently, test compound was added to yield a finalconcentration of 10 μM test compound. After adding 500 μl of a co-factorsolution (cofactor solution: 1 mg/ml glucose-6-phosphate, 1 mg/mlMgCl₂.6H₂O, 0.5 units/ml glucose-6-phosphate dehydrogenase in 0.5 Mphohsphate buffer pH 7.4), homogenisation buffer (homogenisation buffer:1.15% KCl in 0.05 M phosphate buffer, pH 7.4) was added to give a finalvolume of 1 ml. The incubations, 30 or 120 minutes at 37° C., wereinitiated by adding 10 μl of a solution of nicotinamide adeninedinucleotide phosphate (1.25 mg/ml) in homogenisation buffer. After apreincubation during 5 minutes at 37° C., the tubes were continuouslyshaken at 100 oscillations/minute in a water bath. The reactions wereterminated by addition of an equal volume of DMSO. Blank incubationscontaining boiled microsomal fractions were incubated under the sameconditions as the drug incubations. The degree of metabolism wasdetermined by direct measurement of the residual parent compound in thereaction mixture using LC-MS. In parallel, the residual anti-HIVactivity in the reaction mixture was detected using a colorimetricanti-HIV assay as described in Pauwels et al. J. Virol. Methods 1988(20) 309-321. The residual activity is defined as the percent differencein EC₅₀ between the drug incubations and the blank incubations.

The results in Table 6 indicate that compound 2 underwent little or nohepatic first pass metabolization. The same result was obtained forother compounds like compound numbers 11, 13 and 17.

TABLE 6 Microsomal metabolization. Compound name Compound 2Concentration 10 μM DLM (0 min) (in %) 100 DLM (30 min) (in %) 91 DLM(120 min) (in %) 108 HLM (0 min) (in %) 100 HLM (30 min) (in %) 98 HLM(120 min) (in %) 128 The amount of compound was determined using LC-MSat the time points indicated between brackets. The results are indicatedas a % vis-à-vis the amount determined at the start of the experiment(time = 0; normalized to 100%). DLM: dog liver microsomes, HLM: humanliver microsomes, min: minutes.

Antiviral Analyses:

The compounds of the present invention were examined for anti-viralactivity in a cellular assay. The assay demonstrated that thesecompounds exhibit potent anti-HIV activity against a wild typelaboratory HIV strain (HIV-1 strain LAI). The cellular assay wasperformed according to the following procedure.

HIV- or mock-infected MT4 cells were incubated for five days in thepresence of various concentrations of the inhibitor. At the end of theincubation period, the replicating virus in the control cultures haskilled all HIV-infected cells in the absence of any inhibitor. Cellviability was determined by measuring the concentration of MTT, ayellow, water soluble tetrazolium dye that is converted to a purple,water insoluble formazan in the mitochondria of living cells only. Uponsolubilization of the resulting formazan crystals with isopropanol, theabsorbance of the solution was monitored at 540 nm. The values correlatedirectly to the number of living cells remaining in the culture at thecompletion of the five day incubation. The inhibitory activity of thecompound was monitored on the virus-infected cells and was expressed asEC₅₀ and EC₉₀. These values represent the amount of the compoundrequired to protect 50% and 90%, respectively, of the cells from thecytopathogenic effect of the virus. The toxicity of the compound wasmeasured on the mock-infected cells and was expressed as CC₅₀, whichrepresents the concentration of compound required to inhibit the growthof the cells by 50%. The selectivity index (SI) (ratio CC₅₀/EC₅₀) is anindication of the selectivity of the anti-HIV activity of the inhibitor.Wherever results are reported as e.g. pEC₅₀ or pCC₅₀ values, the resultis expressed as the negative logarithm of the result expressed as EC₅₀or CC₅₀ respectively.

Because of the increasing emergence of drug resistant HIV strains, thepresent compounds were also tested for their potency against clinicallyisolated HIV strains harbouring several mutations (Tables 1 and 7).These mutations are associated with resistance to reverse transcriptaseinhibitors and result in viruses that show various degrees of phenotypiccross-resistance to the currently commercially available drugs such asfor instance AZT, didanosine, nevirapine, lamivudine and zalcibatine.

Results:

As a measure of the broad spectrum activity of the present compounds,the EC₅₀ was determined. Table 7 shows the results of the antiviraltesting of the respective compounds expressed in pEC₅₀. The foldresistance rounded to the nearest integer is mentioned between brackets.

As can be seen in this table, the present compounds are effective ininhibiting a broad range of mutant strains: Row A: pEC₅₀ value towardsmutant A, Row B: pEC₅₀ towards mutant B Row C: pEC₅₀ towards mutant C,Row D: pEC₅₀ towards mutant D, Row E: pEC₅₀ towards mutant E, Row F:pEC₅₀ towards mutant F, Row G: pEC₅₀ towards mutant G, Row H: pEC₅₀towards mutant G, Row H: pEC₅₀ towards mutant H, Row I: pEC₅₀ towardsmutant I, Row J: pEC₅₀ towards mutant J, Row K: pEC₅₀ towards mutant K,Row HIV-2: pEC₅₀ towards mutant HIV-2, Row SIV (simian immunodeficiencyvirus): pEC₅₀ towards mutant SIV. Row WT: pEC₅₀ against wild typeHIV-LAI strain. The toxicity (Tox) is expressed as the pCC₅₀ value asdetermined with mock transfected cells. ND means not determined.

TABLE 7 Results of the toxicity testing and the resistance testing.Strain Compound 1 Compound 2 WT 6.5 7.6 A 5.6 (8) 7.0 (4) B 5.9 (4) 7.5(1) C 5.6 (8) 7.1 (3) D 6.0 (3) 7.3 (2) E 5.7 (6) 7.2 (3) F 5.9 (4) 7.4(2) G 6.2 (2) 7.2 (3) H 5.8 (5) 6.9 (5) I 6.1 (3) 7.2 (3) J 5.8 (5) 6.9(5) K 6.5 (1) 7.0 (4) HIV-2 5.2 6.6 SIV 5.1 6.5 Tox <4.49 <4.49

For comparative purposes,2-(dimethylamino)-4,5-dihydro-5-methyl-1-(4-nitrophenyl)-4-(2-oxopropyl)-1H-pyrido[3,2-b]indole-3-carbonitrileas mentioned in WO 02/055520 has a pEC₅₀ for wild type HIV virus of 5.5indicating an increase in potency for the compounds of the presentinvention ranging between about 1 and 2 log units.

The other compounds exemplified in the present application have alsobeen tested for their antiviral activity. With respect to their abilityto inhibit the wild-type HIV-LAI strain, the compound numbers 5, 7, 8,9, 11, 12, 13, 14, 15, 16, 17, 18, 21, 23, 25, 26, 27, 28, 29, 32, 35,43, 67, 68, 71 and 72 had an EC₅₀ value of lower than 1 μM. The compoundnumbers 3, 6, 10, 19, 20, 22, 24, 30, 31, 33, 34, 36, 38, 39, 40, 41,42, 46, 47, 48, 49, 51, 52, 53, 56, 62, 66, 69, 70, 73, 76, 81, 82, 84,85, 86, 87, 93, 94, 96, 97, 98, 99, 102, 103, 106, 109, 110, 111, 114,115 and 117 had an EC₅₀ value between 1 μM and 32 μM. The compoundnumbers 37, 44, 45, 50, 57, 58, 63, 79, 80, 83, 89, 90, 91, 92, 95, 100,101, 104, 105, 108, 112, 113, 118, 119 and 120 had an EC₅₀ value ofhigher than 32 μM.

Oral Availability in the Rat and the Dog

Compounds of formula (I) were formulated as a 20 mg/ml solution orsuspension in DMSO, PEG400 or cyclodextin 40% (CD40%) in water. For mostexperiments in the rat, three dosing groups were formed: 1/singleintraperitoneal dose at 20 mg/kg using the DMSO formulation; 2/singleoral dose at 20 mg/kg using the PEG400 formulation and 3/single oraldose at 20 mg/kg using the cyclodextrin formulation. Blood was sampledat regular time intervals after dosing and drug concentrations in theserum were determined using a LC-MS bioanalytical method.

Formulation

Active ingredient, in casu a compound of formula (I), can be dissolvedin organic solvent such as ethanol, methanol or methylene chloride,preferably, a mixture of ethanol and methylene chloride. Polymers suchas polyvinylpyrrolidone copolymer with vinyl acetate (PVP-VA) orhydroxypropylmethylcellulose (HPMC), typically 5 mPa·s, can be dissolvedin organic solvents such as ethanol, methanol methylene chloride.Suitably the polymer can be dissolved in ethanol. The polymer andcompound solutions can be mixed and subsequently spray dried. The ratioof compound/polymer can be selected from 1/1 to 1/6. Intermediate rangescan be 1/1.5 and 1/3. A suitable ratio can be 1/6. The spray-driedpowder, a solid dispersion, can subsequently be filled in capsules foradministration. The drug load in one capsule can range between 50 and100 mg depending on the capsule size used.

Film-Coated Tablets Preparation of Tablet Core

A mixture of 100 g of active ingredient, in casu a compound of formula(I), 570 g lactose and 200 g starch can be mixed well and thereafterhumidified with a solution of 5 g sodium dodecyl sulfate and 10 gpolyvinylpyrrolidone in about 200 ml of water. The wet powder mixturecan be sieved, dried and sieved again. Then there can be added 100 gmicrocrystalline cellulose and 15 g hydrogenated vegetable oil. Thewhole can be mixed well and compressed into tablets, giving 10.000tablets, each comprising 10 mg of the active ingredient.

Coating

To a solution of 10 g methylcellulose in 75 ml of denatured ethanolthere can be added a solution of 5 g of ethylcellulose in 150 ml ofdichloromethane. Then there can be added 75 ml of dichloromethane and2.5 ml 1,2,3-propanetriol. 10 g of polyethylene glycol can be molten anddissolved in 75 ml of dichloromethane. The latter solution can be addedto the former and then there can be added 2.5 g of magnesiumoctadecanoate, 5 g of polyvinylpyrrolidone and 30 ml of concentratedcolor suspension and the whole can be homogenated. The tablet cores canbe coated with the thus obtained mixture in a coating apparatus.

1-27. (canceled)
 28. A method of treating or combating infection ordisease associated with infection with HIV virus comprisingadministering to a human subject in need of such treatment an effectiveamount of a. compound of formula (I)

or a pharmaceutically acceptable salt or stereoisomeric form, wherein nis 1, 2 or 3; R₁ is hydrogen, cyano, halo, aminocarbonyl,hydroxycarbonyl, C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, arylaminocarbonyl,N-(aryl)-N—(C₁₋₄alkyl)aminocarbonyl, methanimidamidyl,N-hydroxy-methanimidamidyl, or mono- or di(C₁₋₄alkyl)methanimidamidyl,or Het₁; R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl,wherein said C₁₋₁₀alkyl, C₂₋₁₀alkenyl and C₃₋₇cycloalkyl, eachindividually and independently, may be optionally substituted with asubstituent selected from the group consisting of cyano, NR_(4a)R_(4b),pyrrolidinyl, piperidinyl, homopiperidinyl, piperazinyl,4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, thiomorpholinyl,1-oxothiomorpholinyl, 1,1-dioxo-thiomorpholinyl, aryl, furanyl, thienyl,pyrrolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl, isothiazolyl,pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl,pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, hydroxycarbonyl,C₁₋₄alkylcarbonyl, N(R_(4a),R_(4b))carbonyl, C₁₋₄alkyloxycarbonyl,pyrrolidin-1-ylcarbonyl, piperidin-1-ylcarbonyl,homopiperidin-1-ylcarbonyl, piperazin-1-ylcarbonyl,4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl, morpholin-1-ylcarbonyl,thiomorpholin-1-ylcarbonyl, 1-oxothiomorpholin-1-ylcarbonyl and1,1-dioxo-thiomorpholin-1-ylcarbonyl; R₃ is nitro, cyano, amino, halo,hydroxy, C₁₋₄alkyloxy, hydroxycarbonyl, aminocarbonyl,C₁₋₄alkyloxycarbonyl, mono- or di(C₁₋₄alkyl)aminocarbonyl,C₁₋₄alkylcarbonyl, methanimidamidyl, mono- ordi(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or Het₁;R_(4a) is hydrogen, C₁₋₄alkyl or C₁₋₄alkyl substituted with asubstituent selected from the group consisting of amino, mono- ordi(C₁₋₄alkyl)amino, pyrrolidinyl, piperidinyl, homopiperidinyl,piperazinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, thiomorpholinyl,1-oxothiomorpholinyl and 1,1-dioxo-thiomorpholinyl; R_(4b) is hydrogen,C₁₋₄alkyl or C₁₋₄alkyl substituted with a substituent selected from thegroup consisting of amino, mono- or di(C₁₋₄alkyl)amino, pyrrolidinyl,piperidinyl, homopiperidinyl, piperazinyl, 4-(C₁₋₄alkyl)-piperazinyl,morpholinyl, thiomorpholinyl, 1-oxothiomorpholinyl and1,1-dioxo-thiomorpholinyl; aryl is phenyl optionally substituted withone or more substituents each individually selected from the groupconsisting of C₁₋₆alkyl, C₁₋₄alkoxy, halo, hydroxy, amino,trifluoromethyl, cyano, nitro, hydroxyC₁₋₆alkyl, cyanoC₁₋₆alkyl, mono-or di(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl; Het₁ is a 5-membered ring system whereinone, two, three or four ring members are heteroatoms each individuallyand independently selected from the group consisting of nitrogen, oxygenand sulfur, and wherein the remaining ring members are carbon atoms;and, where possible, any nitrogen ring member may optionally besubstituted with C₁₋₄alkyl; any ring carbon atom may, each individuallyand independently, optionally be substituted with a substituent selectedfrom the group consisting of C₁₋₄alkyl, C₂₋₆alkenyl, C₃₋₇cycloalkyl,hydroxy, C₁₋₄alkoxy, halo, amino, cyano, trifluoromethyl,hydroxyC₁₋₄alkyl, cyanoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)amino,aminoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl,aminoC₂₋₆alkenyl, mono- or di(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl,thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, isoxazolyl,isothiazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl,tetrazolyl, aryl, hydroxycarbonyl, aminocarbonyl, C₁₋₄alkyloxycarbonyl,mono- or di(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio; andwherein any of the foregoing furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl and triazolyl moieties may optionally be substituted withC₁₋₄alkyl; provided that the compound of formula (I) is different from2,5-dihydro-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile,and2,5-dihydro-5-methyl-1-(4-nitrophenyl)-2-oxo-1H-pyrido[3,2-b]indole-3-carbonitrile.29. The method according to claim 28 wherein n is 1, R₃ is nitro, R₁ iscyano, C₁₋₄alkyloxycarbonyl or C₁₋₄alkylaminocarbonyl; and R₂ ishydrogen or C₁₋₆alkyl.
 33. The method according to claim 28 wherein n is1 or 2; R₃ is nitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy,hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl, C₁₋₄alkyloxycarbonyl,C₁₋₄alkylcarbonyl, mono- or di(C₁₋₄alkyl)methanimidamidyl,N-hydroxy-methanimidamidyl or Het₁.
 34. The method according to claim 28wherein R₁ is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,C₁₋₄alkyloxycarbonyl, arylaminocarbonyl, N-hydroxy-methanimidamidyl,mono- or di(C₁₋₄alkyl)-methanimidamidyl, or Het₁; and aryl is phenyloptionally substituted with one or more substituents each individuallyselected from the group consisting of C₁₋₆alkyl, C₁₋₄alkoxy, cyano,nitro; and Het₁ is a 5-membered ring system wherein one, two, three orfour ring members are heteroatoms each individually and independentlyselected from the group consisting of nitrogen, oxygen and sulfur, andwherein the remaining ring members are carbon atoms; and, wherepossible, any nitrogen ring member may optionally be substituted withC₁₋₄alkyl; any ring carbon atom may, each individually andindependently, optionally be substituted with a substituent selectedfrom the group consisting of C₁₋₄alkyl, C₃₋₇cycloalkyl, halo, cyano,trifluoromethyl, cyanoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)amino, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, isoxazolyl, aryl, hydroxycarbonyl,C₁₋₄alkyloxycarbonyl, oxo, thio; and wherein the foregoing isoxazolylmay optionally be substituted with C₁₋₄alkyl.
 35. The method accordingto claim 28 wherein R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl,C₃₋₇cycloalkyl or C₁₋₁₀alkyl substituted with substituent selected fromthe group consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl, pyridyl,hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl, C₁₋₄alkyloxycarbonyl or4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl; and R_(4a) is C₁₋₄alkyl; andR_(4b) is C₁₋₄alkyl or C₁₋₄alkyl substituted morpholinyl.
 36. The methodaccording to claim 28 wherein R₂ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl,C₃₋₇cycloalkyl or C₁₋₁₀alkyl substituted with substituent selected fromthe group consisting of cyano, NR_(4a)R_(4b), pyrrolidinyl, piperidinyl,4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl, imidazolyl, pyridyl,hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl, C₁₋₄alkyloxycarbonyl or4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl; and aryl is phenyl optionallysubstituted with one or more substituents each individually selectedfrom the group consisting of C₁₋₆alkyl, C₁₋₄alkoxy, cyano, and nitro.37. The method according to claim 28 wherein R₂ is hydrogen, C₁₋₁₀alkyl,C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or C₁₋₁₀alkyl substituted with substituentselected from the group consisting of cyano, NR_(4a)R_(4b),pyrrolidinyl, piperidinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl,imidazolyl, pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl; and arylis phenyl optionally substituted with one or more substituents eachindividually selected from the group consisting of C₁₋₆alkyl,C₁₋₄alkoxy, cyano, and nitro; and R_(4a) is C₁₋₄alkyl; and R_(4b) isC₁₋₄alkyl or C₁₋₄alkyl substituted morpholinyl.
 38. The method accordingto claim 28 wherein R₃ is nitro, cyano, amino, halo, hydroxy,C₁₋₄alkyloxy, hydroxycarbonyl, aminocarbonyl, aminothiocarbonyl,C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl, mono- ordi(C₁₋₄alkyl)methanimidamidyl, N-hydroxy-methanimidamidyl or Het₁; andHet₁ is a 5-membered ring system wherein one, two, three or four ringmembers are heteroatoms each individually and independently selectedfrom the group consisting of nitrogen, oxygen and sulfur, and whereinthe remaining ring members are carbon atoms; and, where possible, anynitrogen ring member may optionally be substituted with C₁₋₄alkyl; anyring carbon atom may, each individually and independently, optionally besubstituted with a substituent selected from the group consisting ofC₁₋₄alkyl, C₃₋₇cycloalkyl, halo, cyano, trifluoromethyl, cyanoC₁₋₄alkyl,mono- or di(C₁₋₄alkyl)amino, mono- or di(C₁₋₄alkyl)aminoC₂₋₆alkenyl,isoxazolyl, aryl, hydroxycarbonyl, C₁₋₄alkyloxycarbonyl, oxo, thio; andwherein the foregoing isoxazolyl may optionally be substituted withC₁₋₄alkyl.
 39. The method according to claim 28 wherein n is 1; and R₁is hydrogen, cyano, halo, aminocarbonyl, hydroxycarbonyl,C₁₋₄alkyloxycarbonyl, arylaminocarbonyl, N-hydroxy-methanimidamidyl,mono- or di(C₁₋₄alkyl)-methanimidamidyl or Het₁; and R₂ is hydrogen,C₁₋₁₀alkyl, C₂₋₁₀alkenyl, C₃₋₇cycloalkyl or C₁₋₁₀alkyl substituted withsubstituent selected from the group consisting of cyano, NR_(4a)R_(4b),pyrrolidinyl, piperidinyl, 4-(C₁₋₄alkyl)-piperazinyl, morpholinyl, aryl,imidazolyl, pyridyl, hydroxycarbonyl, N(R_(4a)R_(4b))carbonyl,C₁₋₄alkyloxycarbonyl or 4-(C₁₋₄alkyl)-piperazin-1-ylcarbonyl; and R₃ isnitro, cyano, amino, halo, hydroxy, C₁₋₄alkyloxy, hydroxycarbonyl,aminocarbonyl, aminothiocarbonyl, C₁₋₄alkyloxycarbonyl,C₁₋₄alkylcarbonyl, mono- or di(C₁₋₄alkyl)methanimidamidyl,N-hydroxy-methanimidamidyl or Het₁.
 40. The method according to claim 28wherein the compound has the following formula


41. The method according to claim 40 wherein R₃ is nitro.
 42. The methodaccording to claim 40 wherein R₁ is cyano.
 43. The method according toclaim 40 wherein R₁ is C₁₋₄alkyloxycarbonyl or C₁₋₄alkylaminocarbonyl.44. The method according to claim 40 wherein R₂ is C₂₋₆alkyl.
 45. Themethod according to claim 28 wherein n is 1, R₁ is cyano, halo oroxadiazolyl optionally substituted with a substituent selected from thegroup consisting of C₁₋₄alkyl, C₂₋₆alkenyl, C₃₋₇cycloalkyl, hydroxy,C₁₋₄alkoxy, amino, cyano, trifluoromethyl, hydroxyC₁₋₄alkyl,cyanoC₁₋₄alkyl, mono- or di(C₁₋₄alkyl)amino, aminoC₁₋₄alkyl, mono- ordi(C₁₋₄alkyl)aminoC₁₋₄alkyl, arylC₁₋₄alkyl, aminoC₂₋₆alkenyl, mono- ordi(C₁₋₄alkyl)aminoC₂₋₆alkenyl, furanyl, thienyl, pyrrolyl, oxazolyl,thiazolyl, imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl, triazolyl, tetrazolyl, aryl, hydroxycarbonyl,aminocarbonyl, C₁₋₄alkyloxycarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₁₋₄alkylcarbonyl, oxo, thio; and whereinany of the foregoing furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl,imidazolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxadiazolyl,thiadiazolyl and triazolyl moieties may optionally be substituted withC₁₋₄alkyl; R₂ is C₁₋₆alkyl, hydrogen, or C₂₋₆alkenyl; and R₃ is nitro,C₁₋₆alkyl optionally substituted with piperidinyl, pyrrolidinyl,N(R_(4a)R_(4b)), morpholinyl, pyridyl, cyano, or4-(C₁₋₄alkyl)-piperazin-1-yl.
 46. The method according to claim 28wherein the compound is5-Isobutyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-Allyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-Butyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-Ethyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-(2-Morpholin-4-yl-ethyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;5-Methyl-1-(4-nitro-phenyl)-1,5-dihydro-pyrido[3,2-b]indol-2-one;5-But-3-enyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;1-(4-Nitro-phenyl)-2-oxo-5-(2-pyrrolidin-1-yl-ethyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;1-(4-Nitro-phenyl)-2-oxo-5-(2-piperidin-1-yl-ethyl)-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-(3-Dimethylamino-propyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;3-Bromo-5-methyl-1-(4-nitro-phenyl)-1,5-dihydro-pyrido[3,2-b]indol-2-one5-Methyl-1-(3-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;1-(4-Nitro-phenyl)-2-oxo-5-(3-piperidin-1-yl-propyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;5-(4-Morpholin-4-yl-butyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;1-(4-Nitro-phenyl)-2-oxo-5-(4-pyrrolidin-1-yl-butyl)-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;5-[3-(4-Methyl-piperazin-1-yl)-propyl]-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-Cyanomethyl-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-(3-Morpholin-4-yl-propyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;1-(4-Nitro-phenyl)-2-oxo-5-(4-piperidin-1-yl-butyl)-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;5-(4-Dimethylamino-butyl)-1-(4-nitro-phenyl)-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]-indole-3-carbonitrile;1-(4-Nitro-phenyl)-2-oxo-5-pyridin-4-ylmethyl-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile;3-(5-tert-Butyl-[1,2,4]oxadiazol-3-yl)-5-methyl-1-(4-nitro-phenyl)-1,5-dihydro-pyrido[3,2-b]indol-2-one;or5-Methyl-1-(4-nitro-phenyl)-3-(5-trifluoromethyl-[1,2,4]oxadiazol-3-yl)-1,5-dihydro-pyrido[3,2-b]indol-2-one;or a pharmaceutically acceptable salt or stereoisomer thereof.
 47. Themethod according to claim 28 in which the reverse transcriptase of theHIV virus is mutant.